U.S. patent application number 15/650038 was filed with the patent office on 2019-01-17 for antenna structures and isolation chambers of a multi-radio, multi-channel (mrmc) mesh network device.
The applicant listed for this patent is Amazon Technologies, Inc.. Invention is credited to Troy Hulick, In Chul Hyun, Tzung-I Lee.
Application Number | 20190020713 15/650038 |
Document ID | / |
Family ID | 62904616 |
Filed Date | 2019-01-17 |
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United States Patent
Application |
20190020713 |
Kind Code |
A1 |
Hulick; Troy ; et
al. |
January 17, 2019 |
ANTENNA STRUCTURES AND ISOLATION CHAMBERS OF A MULTI-RADIO,
MULTI-CHANNEL (MRMC) MESH NETWORK DEVICE
Abstract
An electronic device includes a metal housing having a height
greater than a width, four sides that form an inner chamber in a
center thereof. Four sidewalls extend from a first back wall form a
first chamber located at a first of the four sides. Four sidewalls
extend from a second back wall form a second chamber located at a
second of the four sides. A first antenna is disposed in the first
chamber. A second antenna is disposed in the second chamber. A
circuit board is disposed within the inner chamber and oriented
longitudinally from a bottom of the inner chamber. A first radio is
disposed on the circuit board and coupled to the first antenna. A
second radio is disposed on the circuit board and coupled to the
second antenna, such that the second antenna is electrically
isolated from the first antenna.
Inventors: |
Hulick; Troy; (Saratoga,
CA) ; Hyun; In Chul; (San Jose, CA) ; Lee;
Tzung-I; (San Jose, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Amazon Technologies, Inc. |
Seattle |
WA |
US |
|
|
Family ID: |
62904616 |
Appl. No.: |
15/650038 |
Filed: |
July 14, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 88/10 20130101;
H01Q 1/2291 20130101; H05K 1/165 20130101; H01Q 1/521 20130101;
H01Q 9/42 20130101; H01Q 1/243 20130101; H05K 2201/10098 20130101;
H01Q 21/205 20130101; H01Q 9/0414 20130101; H01Q 19/106 20130101;
H05K 5/04 20130101; H01Q 1/50 20130101; H05K 2201/0999 20130101;
H01Q 1/44 20130101; H01Q 21/065 20130101; H04L 67/1091 20130101;
H01Q 5/392 20150115; H01Q 21/29 20130101; H01Q 15/14 20130101; H01Q
1/42 20130101; H05K 7/20163 20130101; H05K 2201/09263 20130101;
H04W 40/02 20130101; H01Q 1/12 20130101; H05K 1/0215 20130101; H05K
1/0284 20130101 |
International
Class: |
H04L 29/08 20060101
H04L029/08; H01Q 1/24 20060101 H01Q001/24; H01Q 1/50 20060101
H01Q001/50; H05K 5/04 20060101 H05K005/04; H04W 40/02 20060101
H04W040/02; H01Q 21/29 20060101 H01Q021/29 |
Claims
1. An electronic device: a metal housing having a height greater
than a width of the metal housing, the metal housing comprising
four sides that form an inner chamber in a center of the metal
housing; four sidewalls extending from a first back wall to form a
first chamber located at a first of the four sides; four sidewalls
extending from a second back wall to form a second chamber located
at a second of the four sides; a first antenna disposed in the
first chamber; a second antenna disposed in the second chamber, the
second antenna being electrically isolated from the first antenna;
a circuit board disposed within the inner chamber and oriented
longitudinally from a bottom of the inner chamber; a first radio
disposed on the circuit board and coupled to the first antenna
through one of the four sidewalls or the first back wall of the
first chamber; and a second radio disposed on the circuit board and
coupled to the second antenna through one of the four sidewalls or
the second back wall of the second chamber.
2. The electronic device of claim 1, wherein the four sidewalls
that form the first chamber comprise: two rectangular sidewalls
each angled from a long edge of the first back wall towards a
nearest intersection of two sides of the metal housing; a top
sidewall located between the two rectangular sidewalls and the
first back wall at a top of the first chamber; and a bottom
sidewall located between the two rectangular sidewalls and the
first back wall at a bottom of the first chamber.
3. The electronic device of claim 2, wherein the first side and the
second side are adjacent sides of the metal housing, wherein the
electronic device further comprises: a first printed circuit board
(PCB) on which is disposed a first antenna and a first dual-band
omnidirectional antenna, the first PCB attached to the top sidewall
of the first chamber, wherein the first antenna is coupled to a
third radio disposed on the circuit board, the third radio to
transmit and receive in a cellular frequency, and wherein the first
dual-band omnidirectional antenna is coupled to a fourth radio
disposed on the circuit board; and a second PCB on which is
disposed a second antenna and a second dual-band omnidirectional
antenna, the second PCB attached to a second top sidewall of the
second chamber, wherein the second antenna is coupled to the third
radio disposed on the circuit board, the third radio to transmit
and receive in the cellular frequency, and wherein the second
dual-band omnidirectional antenna is coupled to the fourth radio
disposed on the circuit board.
4. The electronic device of claim 1, wherein the first antenna
comprises: a PCB including a first antenna element having a feed
coupled to the first radio, the PCB being attached to the first
back wall of the first chamber; and an antenna frame made of a
dielectric material and attached to at least two of the four
sidewalls of the first chamber, wherein the antenna frame retains,
within an opening of the antenna frame, a second antenna element at
a predetermined distance from the first antenna element, and
wherein the antenna frame further comprises one or more extension
tabs with a depth sized to the predetermined distance.
5. The electronic device of claim 1, further comprising: four
sidewalls extending from a third back wall to form a third chamber
located at a third of the four sides; four sidewalls extending from
a fourth back wall to form a fourth chamber located at a fourth of
the four sides; a third antenna disposed in the third chamber; a
first switch coupled between the third antenna and the first radio;
a fourth antenna disposed in the fourth chamber, the fourth antenna
being electrically isolated from the third antenna; and a second
switch coupled between the fourth antenna and the second radio.
6. The electronic device of claim 5, further comprising: four
angled sidewalls extending from a fifth back wall to form a top
chamber located at a top of the metal housing; four angled
sidewalls extending from a sixth back wall to form a bottom chamber
located at a bottom of the metal housing; a fifth antenna disposed
in the top chamber; a third radio disposed on the circuit board and
coupled to the fifth antenna through one of the four angled
sidewalls or the fifth back wall of the top chamber; a sixth
antenna disposed within the bottom chamber, the sixth antenna being
electrically isolated from the fifth antenna; and a fourth radio
disposed on the circuit board and coupled to the sixth antenna
through one of the four angled sidewalls or the sixth back wall of
the bottom chamber.
7. The electronic device of claim 6, wherein the fifth antenna
comprises: a PCB including a first antenna element having a feed
coupled to the third radio, the PCB adhered to the fifth back wall
of the top chamber; a foam layer adhered to the PCB, the foam layer
being of a predetermined thickness and including raised strips
formed into an open-faced box positioned on an opposite side of the
foam layer from the first antenna element; and a planar metal
member disposed within the open-faced box of the foam layer.
8. The electronic device of claim 1, further comprising: a first
air baffle assembly comprising a first air baffle and a first
heatsink, wherein the first air baffle and the first heatsink each
has a triangular cross-section, wherein the first air baffle
assembly is elongated and physically attached across a length of a
first side of the circuit board; a second air baffle assembly
comprising a second air baffle and a second heatsink, wherein the
second air baffle and the second heatsink each has a triangular
cross-section, wherein the second air baffle assembly is elongated
and physically attached across a length of a second side of the
circuit board; and a single fan attached to a first end of both the
first air baffle assembly and the second air baffle assembly, and
oriented to pull air from a bottom of the inner chamber and push
the air out a top of the inner chamber.
9. The electronic device of claim 8, wherein the first side and the
second side are adjacent sides of the metal housing, wherein the
electronic device further comprises an air dam positioned in
between the first chamber and the second chamber and running
longitudinally between one of the first air baffle assembly or the
second air baffle assembly and an intersection of two sides of the
metal housing, to deter backflow of air to the bottom of the inner
chamber.
10. The electronic device of claim 8, further comprising a chassis
that covers the metal housing, the chassis comprising: a first side
portion located at a bottom side of the chassis, the first side
portion comprising venting holes through which to pull air; a
second side portion located at a top side of the chassis, the
second side portion being a solid surface; and a top portion
located at the top of the chassis, the top portion comprising
exhaust holes through which to push out air exhaust after exiting
the top of the inner chamber.
11. An electronic device comprising: a metal housing, having a
height greater than a width, the metal housing comprising: a
plurality of sides that form an inner chamber in a center of the
metal housing; four sidewalls extending from a first back wall that
form a first chamber of a plurality of chambers, wherein each
chamber of the plurality of chambers correspond to one of the
plurality of sides, and wherein the four sidewalls comprise: a
first rectangular sidewall angled from a first long edge of the
first back wall towards a nearest first adjacent side of the
plurality of sides; a second rectangular sidewall angled from a
second long edge of the first back wall towards a nearest second
adjacent side of the plurality of sides; a top sidewall located
between the first and second rectangular sidewalls and the first
back wall at the top of the first chamber; and a bottom sidewall
located between the first and second rectangular sidewalls and the
first back wall at the bottom of the chamber; and a circuit board
disposed within the inner chamber and oriented longitudinally from
a bottom of the inner chamber; a first antenna disposed in the
first chamber of the plurality of chambers; a second antenna
disposed in a second chamber of the plurality of chambers, wherein
the second antenna is electrically isolated from the first antenna;
a first radio disposed on the circuit board and coupled to the
first antenna; and a second radio disposed on the circuit board and
coupled to the second antenna.
12. The electronic device of claim 11, wherein the first antenna
comprises: a printed circuit board (PCB) including a first antenna
element having an antenna feed coupled to the first radio, the PCB
being attached to the first back wall of the first chamber; a
conductive foam positioned between the PCB and the first back wall;
and an antenna frame made of a polymer and attached to the first
and second rectangular sidewalls, wherein the antenna frame forms
an opening adapted to retain a second antenna element at a
predetermined distance from the first antenna element.
13. The electronic device of claim 11, further comprising: four
angled sidewalls extending from a third back wall that form a top
chamber located at a top of the metal housing; four angled
sidewalls extending from a fourth back wall that form a bottom
chamber located at a bottom of the metal housing; a third antenna
disposed in the top chamber; a third radio disposed on the circuit
board and coupled to the third antenna through one of the four
angled sidewalls or the third back wall of the top chamber; a
fourth antenna disposed within the bottom chamber, the fourth
antenna being electrically isolated from the third antenna; and a
fourth radio disposed on the circuit board and coupled to the
fourth antenna through the four angled sidewalls or the fourth back
wall of the bottom chamber.
14. The electronic device of claim 13, wherein the fourth antenna
comprises: a PCB including a first antenna element having a feed
coupled to the fourth radio, the PCB attached to the fourth back
wall of the bottom chamber; a conductive foam positioned between
the PCB and the fourth back wall; and an antenna frame made of a
polymer and attached to the four angled sidewalls, wherein the
antenna frame forms an opening adapted to retain a second antenna
element at a predetermined distance from the first antenna
element.
15. The electronic device of claim 11, further comprising: a
support bracket attached to the circuit board to extend a width of
the circuit board; a communication device attached to both the
circuit board and the support bracket; a storage device attached to
both the circuit board and the support bracket, wherein the support
bracket is sized to fit at least partially between two adjacent
ones of the plurality of chambers; and a shield cover adapted to
completely cover the storage device, wherein the shield cover
includes tab extensions to attach the storage device to the support
bracket.
16. An electronic device comprising: an elongated metal housing
having fours sides, a top, and a bottom, the elongated metal
housing comprising: an inner chamber formed within a center of the
four sides, the top, and the bottom of the elongated metal housing;
a first metal section that forms a first chamber located on a first
side of the four sides; a second metal section that forms a second
chamber located on a second side of the four sides; a third metal
section that forms a third chamber located on a third side of the
four sides; a fourth metal section that forms a fourth chamber
located on a fourth side of the four sides, wherein each of the
first, second, third, and fourth chambers is shaped as a truncated
triangular prism structure defined by a first back wall, a top
sidewall, a bottom sidewall, and a pair of angled sidewalls; a
fifth metal section that forms a top chamber located at the top of
the elongated metal housing; and a sixth metal section that forms a
bottom chamber located at a bottom of the elongated metal housing,
wherein each of the top chamber and the bottom chamber is shaped as
a truncated pyramid structure defined by a second back wall and
four angled sidewalls; four first antennas each of which is coupled
to the first back wall of respective ones of the first, second,
third, and fourth chambers; two second antennas each of which is
coupled to the second back wall of respective ones of the top
chamber and the bottom chamber; a circuit board disposed within the
inner chamber and oriented longitudinally from a bottom of the
inner chamber towards a top of the inner chamber; and four radios
disposed on the circuit board, wherein each of two of the four
radios is coupled to one of the four first antennas through a
corresponding first back wall, and each of another two radios of
the four radios is coupled to one of the two second antennas
through a corresponding second back wall.
17. The electronic device of claim 16, wherein each of the four
first antennas comprises: a PCB including a first antenna element
having a radio feed, the PCB being elongated and coupled to the
first back wall; and an antenna frame made of a polymer and
attached to the pair of angled sidewalls, wherein the antenna frame
forms an opening adapted to retain a second antenna element at a
predetermined distance from the first antenna element, and wherein
the antenna frame includes one or more extension tabs with a depth
sized to the predetermined distance.
18. The electronic device of claim 16, wherein each of the two
second antennas comprises: a PCB including a first antenna element
having a radio feed, the PCB coupled to the second back wall; and
an antenna frame made of a polymer and attached to the four angled
sidewalls, wherein the antenna frame forms an opening adapted to
retain a second antenna element at a predetermined distance from
the first antenna element, and wherein the antenna frame comprises
one or more extension tabs with a depth sized to the predetermined
distance.
19. The electronic device of claim 16, wherein at least one of the
four first antennas comprises: a PCB including a first antenna
element having a radio feed, the PCB adhered to the first back
wall; a foam layer adhered to the PCB, the foam layer being of a
predetermined thickness and including raised strips formed into an
open-faced box positioned on an opposite side of the foam layer
from the first antenna element; and a planar metal member disposed
within the open-faced box of the foam layer.
20. The electronic device of claim 16, further comprising: a first
air baffle assembly comprising a first air baffle and a first
heatsink, wherein the first air baffle and the first heatsink each
has a triangular cross-section, wherein the first air baffle
assembly is elongated and physically attached across a length of a
first side of the circuit board; a second air baffle assembly
comprising a second air baffle and a second heatsink, wherein the
second air baffle and the second heatsink each has a triangular
cross-section, wherein the second air baffle assembly is elongated
and physically attached across a length of a second side of the
circuit board; and a single fan attached to a first end of both the
first air baffle assembly and the second air baffle assembly, and
oriented to pull air from a bottom of the inner chamber and push
the air out the top of the inner chamber.
Description
BACKGROUND
[0001] A large and growing population of users is enjoying
entertainment through the consumption of digital media items, such
as music, movies, images, electronic books, and so on. The users
employ various electronic devices to consume such media items.
Among these electronic devices (referred to herein as user devices)
are electronic book readers, cellular telephones, personal digital
assistants (PDAs), portable media players, tablet computers,
netbooks, laptops and the like. These electronic devices wirelessly
communicate with a communications infrastructure to enable the
consumption of the digital media items. In order to wirelessly
communicate with other devices, these electronic devices include
one or more antennas.
BRIEF DESCRIPTION OF DRAWINGS
[0002] The present inventions will be understood more fully from
the detailed description given below and from the accompanying
drawings of various embodiments of the present invention, which,
however, should not be taken to limit the present invention to the
specific embodiments, but are for explanation and understanding
only.
[0003] FIG. 1 is a network diagram of network hardware devices
organized in a wireless mesh network (WMN) for content distribution
to client devices in an environment of limited connectivity to
broadband Internet infrastructure according to one embodiment.
[0004] FIG. 2 is a block diagram of a network hardware device with
five radios operating concurrently in a WMN according to one
embodiment.
[0005] FIG. 3 is a block diagram of a mesh node with multiple
radios according to one embodiment.
[0006] FIG. 4 is a block diagram of a mesh network device according
to one embodiment.
[0007] FIG. 5A illustrates a multi-radio, multi-channel (MRMC)
network device according to one embodiment.
[0008] FIG. 5B illustrates a set of radiation patterns of the MRMC
device of FIG. 5A according to one embodiment.
[0009] FIG. 6A illustrates a phased array patch antenna on a
printed circuit board (PCB) according to one embodiment.
[0010] FIG. 6B illustrates a phased array patch antenna on a PCB
according to another embodiment.
[0011] FIG. 6C illustrates the phased array patch antenna of FIG.
6B within one of a top chamber or a bottom chamber of the MRMC
device of FIG. 5A, according to one embodiment.
[0012] FIG. 7A illustrates a combination omnidirectional antenna in
which a wireless wide area network (WWAN) antenna and a wireless
local area network (WLAN) antenna share a common ground on a PCB,
according to one embodiment.
[0013] FIG. 7B illustrates a combination omnidirectional antenna in
which a WWAN antenna and a WLAN antenna share a common ground on a
PCB, according to another embodiment.
[0014] FIG. 8 illustrates a foam-layer-based patch antenna
integrated within a chamber of the MRMC network device of FIG. 5A
according to an alternative embodiment.
[0015] FIGS. 9A, 9B, 9C, 9D, and 9E illustrate a polymer-based
patch antenna within a chamber of the MRMC network device of FIG.
5A according to one embodiment.
[0016] FIG. 10A illustrates an exploded view of a side antenna
assembly, according to one embodiment.
[0017] FIG. 10B illustrates a completely assembled side antenna
assembly, according to one embodiment.
[0018] FIG. 11A illustrates an exploded view of a top (or bottom)
antenna assembly, according to one embodiment.
[0019] FIG. 11B illustrates a completely assembled top (or bottom)
antenna assembly, according to one embodiment.
[0020] FIG. 12 illustrates a partially exploded view of the MRMC
network device of FIG. 5A, including two side antenna assemblies, a
top antenna assembly, and a bottom antenna assembly, according to
one embodiment.
[0021] FIG. 13A illustrates a first air baffle assembly that cools
a main circuit board of the MRMC device of FIG. 5A according to one
embodiment.
[0022] FIG. 13B illustrates a second air baffle assembly that also
cools the main circuit board of the MRMC device of FIG. 5B
according to one embodiment.
[0023] FIG. 14 illustrates an exploded view of an air cooling
system, main circuit board, and support bracket according to one
embodiment.
[0024] FIG. 15A illustrates a side view of the assembled air
cooling system, main circuit board, and support bracket according
to one embodiment.
[0025] FIGS. 15B and 15C illustrate a shield cover for attaching a
storage device to both the support bracket and the main circuit
board according to one embodiment.
[0026] FIG. 16 illustrates a perspective view of a
partially-assembled MRMC network device with placement of the
assembled air cooling system, main circuit board, and support
bracket (FIG. 15A), according to one embodiment.
[0027] FIG. 17A illustrates an exploded view of a radio frequency
(RF) shield and coax cable retention system according to one
embodiment.
[0028] FIG. 17B illustrates an assembled view of the RF shield and
coax cable retention system of FIG. 17A.
[0029] FIG. 18 illustrates an almost-complete assembly of the MRMC
network device according to one embodiment.
[0030] FIG. 19A illustrates a complete assembly of the MRMC network
device according to one embodiment.
[0031] FIG. 19B illustrates the complete assembly of the MRMC
network device together with a chassis placed over the outside of
the metal housing of FIG. 5A, according to one embodiment.
DETAILED DESCRIPTION
[0032] A wireless mesh network (WMN) containing multiple mesh
network devices, organized in a mesh topology, is described. The
mesh network devices in the WMN cooperate in distribution of
content files to client consumption devices in an environment of
limited connectivity to broadband Internet infrastructure. The
embodiments described herein may be implemented where there is the
lack, or slow rollout, of suitable broadband Internet
infrastructure in developing nations, for example. These mesh
networks can be used in the interim before broadband Internet
infrastructure becomes widely available in those developing
nations.
[0033] One system of devices organized in a WMN includes a first
network hardware device having at least one of a point-to-point
wireless link to access content files over the Internet or a wired
connection to access the content files stored on a storage device
coupled to the first network hardware device. The network hardware
devices are also referred to herein as mesh routers, mesh network
devices, mesh nodes, Meshboxes, or Meshbox nodes. Multiple network
hardware devices wirelessly are connected through a network
backbone formed by multiple peer-to-peer (P2P) wireless connections
(i.e., wireless connections between multiple pairs of the network
hardware devices). The multiple network devices are wirelessly
connected to one or more client consumption devices by
node-to-client (N2C) wireless connections. The multiple network
devices are wirelessly connected to a mesh network control service
(MNCS) device by cellular connections. The cellular connections may
have lower bandwidths than the point-to-point wireless link.
[0034] A second network hardware device is wirelessly connected to
the first network hardware device over a first P2P connection.
During operation, the second network hardware device is wirelessly
connected to a first client consumption device over a first N2C
connection. The second network hardware device receives a first
request for a first content file from the first client consumption
device over the first N2C connection. The second hardware device
sends a second request for the first content file to the first
network hardware device over the first P2P connection. The second
hardware device receives the first content file from the first
network hardware device over the first P2P connection and sends the
first content file to the first client consumption device over the
first N2C connection. The content file (or generally a content item
or object) may be any type of format of digital content, including,
for example, electronic texts (e.g., eBooks, electronic magazines,
digital newspapers, etc.), digital audio (e.g., music, audible
books, etc.), digital video (e.g., movies, television, short clips,
etc.), images (e.g., art, photographs, etc.), or multi-media
content. The client consumption devices may include any type of
content rendering devices such as electronic book readers, portable
digital assistants, mobile phones, laptop computers, portable media
players, tablet computers, cameras, video cameras, netbooks,
notebooks, desktop computers, gaming consoles, DVD players, media
centers, and the like.
[0035] The embodiments of the mesh network devices may be used to
deliver content, such as video, music, literature, or the like, to
users who do not have access to broadband Internet connections
because the mesh network devices may be deployed in an environment
of limited connectivity to broadband Internet infrastructure. In
some of the embodiments described herein, the mesh network
architecture does not include "gateway" nodes that are capable of
forwarding broadband mesh traffic to the Internet. The mesh network
architecture may include a limited number of point-of-presence
(POP) nodes that do have access to the Internet, but the majority
of mesh network devices is capable of forwarding broadband mesh
traffic between the mesh network devices for delivering content to
client consumption devices that would otherwise not have broadband
connections to the Internet. Alternatively, instead of a POP node
having access to broadband Internet infrastructure, the POP node is
coupled to storage devices that store the available content for the
WMN. The WMN may be self-contained in the sense that content lives
in, travels through, and is consumed by nodes in the mesh network.
In some embodiments, the mesh network architecture includes a large
number of mesh nodes, called Meshbox nodes. From a hardware
perspective, the Meshbox node functions much like an
enterprise-class router with the added capability of supporting P2P
connections to form a network backbone of the WMN. From a software
perspective, the Meshbox nodes provide much of the capability of a
standard content distribution network (CDN), but in a localized
manner. The WMN can be deployed in a geographical area in which
broadband Internet is limited. The WMN can scale to support a
geographic area based on the number of mesh network devices, and
the corresponding distances for successful communications over WLAN
channels by those mesh network devices.
[0036] Although various embodiments herein are directed to content
delivery, such as for the Amazon Instant Video (AIV) service, the
WMNs, and corresponding mesh network devices, can be used as a
platform suitable for delivering high bandwidth content in any
application where low latency is not critical or access patterns
are predictable. The embodiments described herein are compatible
with existing content delivery technologies, and may leverage
architectural solutions, such as CDN surfaces like the Amazon AWS
CloudFront service. Amazon CloudFront CDN is a global CDN service
that integrates with other Amazon Web services products to
distribute content to end users with low latency and high data
transfer speeds. The embodiments described herein can be an
extension to this global CDN, but in environments where there is
limited broadband Internet infrastructure. The embodiments
described herein may provide users in these environments with a
content delivery experience equivalent to what the users would
receive on a traditional broadband Internet connection. The
embodiments described herein may be used to optimize deployment for
traffic types (e.g., streaming video) that are increasingly
becoming a significant percentage of broadband traffic and taxing
existing infrastructure in a way that is not sustainable.
[0037] FIGS. 1-3 are generally directed to network hardware
devices, organized in a wireless mesh network, for content
distribution to client consumption devices in environments of
limited connectivity to broadband internet infrastructure. FIGS.
5-19 are generally directed to embodiments of antenna structures
and isolations chambers of a multi-radio, multi-channel (MRMC) mesh
network device.
[0038] FIG. 1 is a network diagram of network hardware devices
102-110, organized in a wireless mesh network (WMN) 100, for
content distribution to client devices in an environment of limited
connectivity to broadband Internet infrastructure according to one
embodiment. The WMN 100 includes multiple network hardware devices
102-110 that connect together to transfer digital content through
the WMN 100 to be delivered to one or more client consumption
devices connected to the WMN 100. In the depicted embodiment, the
WMN 100 includes a miniature point-of-presence (mini-POP) device
102 (also referred to as mini-POP device), having at least one of a
first wired connection to an attached storage device 103 or a
point-to-point wireless connection 105 to a CDN device 107 (server
of a CDN or a CDN node) of an Internet Service Provider (ISP). The
CDN device 107 may be a POP device (also referred to as a POP
device), an edge server, a content server device or another device
of the CDN. The mini-POP device 102 may be similar to POP devices
of a CDN in operation. However, the mini-POP device 102 is called a
miniature to differentiate it from a POP device of a CDN given the
nature of the mini-POP device 102 being a single ingress point to
the WMN 100; whereas, the POP device of a CDN may be one of many in
the CDN.
[0039] The point-to-point wireless connection 105 may be
established over a point-to-point wireless link 115 between the
mini-POP device 102 and the CDN device 107. Alternatively, the
point-to-point wireless connection 105 may be established over a
directional microwave link between the mini-POP device 102 and the
CDN device 107. In other embodiments, the mini-POP device 102 is a
single ingress node of the WMN 100 for the content files stored in
the WMN 100. Meaning the mini-POP 102 may be the only node in the
WMN 100 having access to the attached storage or a communication
channel to retrieve content files stored outside of the WMN 100. In
other embodiments, multiple mini-POP devices may be deployed in the
WMN 100, but the number of mini-POP devices should be much smaller
than a total number of network hardware devices in the WMN 100.
Although a point-to-point wireless connection can be used, in other
embodiments, other communication channels may be used. For example,
a microwave communication channel may be used to exchange data.
Other long distance communication channels may be used, such as a
fiber-optic link, satellite link, cellular link, or the like. The
network hardware devices of the WMN 100 may not have direct access
to the mini-POP device 102, but can use one or more intervening
nodes to get content from the mini-POP device. The intervening
nodes may also cache content that can be accessed by other nodes.
The network hardware devices may also determine a shortest possible
route between the requesting node and a node where a particular
content file is stored.
[0040] The CDN device 107 may be located at a datacenter 119 and
may be connected to the Internet 117. The CDN device 107 may be one
of many devices in the global CDN and may implement the Amazon
CloudFront technology. The CDN device 107 and the datacenter 119
may be co-located with the equipment of the point-to-point wireless
link 155. The point-to-point wireless connection 105 can be
considered a broadband connection for the WMN 100. In some cases,
the mini-POP device 102 does not have an Internet connection via
the point-to-point wireless connection 105 and the content is
stored only in the attached storage device 103 for a self-contained
WMN 100.
[0041] The WMN 100 also includes multiple mesh nodes 104-110 (also
referred to herein as meshbox nodes and network hardware devices).
The mesh nodes 104-110 may establish multiple P2P wireless
connections 109 between mesh nodes 104-110 to form a network
backbone. It should be noted that only some of the possible P2P
wireless connections 109 are shown between the mesh nodes 104-110
in FIG. 1. In particular, a first mesh node 104 is wirelessly
coupled to the mini-POP device 102 via a first P2P wireless
connection 109, as well as being wirelessly coupled to a second
mesh node 106 via a second P2P wireless connection 109 and a third
mesh node 108 via a third P2P wireless connection. The mesh nodes
104-110 (and the mini-POP device 102) are MRMC mesh network
devices. As described herein, the mesh nodes 104-110 do not
necessarily have reliable access to the CDN device 107. The mesh
nodes 104-110 (and the mini-POP device 102) wirelessly communicate
with other nodes via the network backbone via a first set of WLAN
channels reserved for inter-node communications. The mesh nodes
102-110 communicate data with one another via the first set of WLAN
channels at a first frequency of approximately 5 GHz (e.g., 5 GHz
band of the Wi-Fi.RTM. network technologies).
[0042] Each of the mesh nodes 104-110 (and the mini-POP device 102)
also includes multiple node-to-client (N2C) wireless connections
111 to wirelessly communicate with one or more client consumption
devices via a second set of WLAN channels reserved for serving
content files to client consumption devices connected to the WMN
100. In particular, the second mesh node 106 is wirelessly coupled
to a first client consumption device 112 (AIV client) via a first
N2C wireless connection 111, a second client consumption device 114
(AIV client) via a second N2C wireless connection 111, and a third
client consumption device 116 (e.g., the Fire TV device) via a
third N2C wireless connection 111. The second node 106 wirelessly
communicates with the client consumption devices via the second set
of WLAN channels at a second frequency of approximately 2.4 GHz
(e.g., 2.4 GHz band of the Wi-Fi.RTM. network technologies).
[0043] Each of the mesh nodes 104-110 (and the mini-POP device 102)
also includes a cellular connection 113 to wirelessly communicate
control data between the respective node and a second device 118
hosting a mesh network control service described below. The
cellular connection 113 may be a low bandwidth, high availability
connection to the Internet 117 provided by a cellular network. The
cellular connection 113 may have a lower bandwidth than the
point-to-point wireless connection 105. There may be many uses for
this connection including, health monitoring of the mesh nodes,
collecting network statistics of the mesh nodes, configuring the
mesh nodes, and providing client access to other services. In
particular, the mesh node 110 connects to a cellular network 121
via the cellular connection 113. The cellular network 121 is
coupled to the second device 118 via the Internet 117. The second
device 118 may be one of a collection of devices organized as a
cloud computing system that hosts one or more services 120. The
services 120 may include cloud services to control setup of the
mesh nodes, the content delivery service (e.g., AIV origin), as
well as other cloud services. The mesh network control service can
be one or more cloud services. The cloud services can include a
metric collector service, a health and status service, a link
selection service, a channel selection service, a content request
aggregation service, or the like. There may be APIs for each of
these services. Although this cellular connection may provide
access to the Internet 117, the amount of traffic that goes through
this connection should be minimized, since it may be a relatively
costly link. This cellular connection 113 may be used to
communicate various control data to configure the mesh network for
content delivery. In addition, the cellular connection 113 can
provide a global view of the state of the WMN 100 remotely. Also,
the cellular connection 113 may aid in the debugging and
optimization of the WMN 100. In other embodiments, other low
bandwidth services may also be offered through this link (e.g.
email, shopping on Amazon.com, or the like).
[0044] Although only four mesh nodes 104-110 are illustrated in
FIG. 1, the WMN 100 can use many mesh nodes, wirelessly connected
together in a mesh network, to move content through the WMN 100.
The 5 GHz WLAN channels are reserved for inter-node communications
(i.e., the network backbone). Theoretically, there is no limit to
the number of links a given Meshbox node can have to its neighbor
nodes. However, practical considerations, including memory, routing
complexity, physical radio resources, and link bandwidth
requirements, may place a limit on the number of links maintained
to neighboring mesh nodes. Meshbox nodes may function as
traditional access points (APs) for devices running AIV client
software. The 2.4 GHz WLAN channels are reserved for serving client
consumption devices. The 2.4 GHz band may be chosen for serving
clients because there is a wider device adoption and support for
this band. Additionally, the bandwidth requirements for serving
client consumption devices will be lower than that of the network
backbone. The number of clients that each Meshbox node can support
depends on a number of factors including memory, bandwidth
requirements of the client, incoming bandwidth that the Meshbox
node can support, and the like. For example, the Meshbox nodes
provide coverage to users who subscribe to the content delivery
service and consume that service through an AIV client on the
client consumption devices (e.g., a mobile phone, a set top box, a
tablet, or the like). It should be noted that there is a 1-to-many
relationship between Meshbox nodes and households (not just between
nodes and clients). This means the service can be provided without
necessarily requiring a customer to have a Meshbox node located in
their house, as illustrated in FIG. 1. As illustrated, the second
mesh node 106 services two client consumption devices 112, 114
(e.g., AIV clients) located in a first house, as well as a third
client consumption device 116 (e.g., the Fire TV client) located in
a second house. The Meshbox nodes can be located in various
structures, and there can be multiple Meshbox nodes in a single
structure.
[0045] The WMN 100 may be used to address two main challenges:
moving high bandwidth content to users and storing that content in
the network itself. The first challenge may be addressed in
hardware through the radio links between mesh nodes and the radio
links between mesh nodes and client consumption devices, and in
software by the routing protocols used to decide where to push
traffic and link and channel management used to configure the WMN
100. The second challenge may be addressed by borrowing from the
existing content distribution strategy employed by the content
delivery services (e.g., AIV) using caches of content close to the
user. The architecture to support content caching is known as a
CDN. An example CDN implementation is the AWS CloudFront service.
The AWS CloudFront service may include several point-of-presence
(POP) racks that are co-located in datacenters that see a lot of
customer traffic (for example an ISP), such as illustrated in
datacenter 119 in FIG. 1. A POP rack has server devices to handle
incoming client requests and storage devices to cache content for
these requests. If the content is present in the POP rack, the
content is served to the client consumption device from there. If
it is not stored in the POP rack, a cache miss is triggered and the
content is fetched from the next level of cache, culminating in the
"origin," which is a central repository for all available content.
In contrast, as illustrated in FIG. 1, the WMN 100 includes the
mini-POP device 102 that is designed to handle smaller amounts of
traffic than a typical POP rack. Architecturally, the mini-POP
device 102 may be designed as a Meshbox node with storage attached
(e.g. external hard disk). The mini-POP device 102 may function
identically to a POP device with the exception of how cache misses
are handled. Because of the lack of broadband Internet
infrastructure, the mini-POP device 102 has no traditional Internet
connection to the next level of cache. The following describes two
different solutions for providing the next level of cache to the
mini-POP device 102.
[0046] In one embodiment, the mini-POP device 102 is coupled to an
existing CDN device 107 via a directional microwave link or other
point-to-point wireless link 115. A directional microwave link is a
fairly easy way to get a relatively high bandwidth connection
between two points. However, line of sight is required which might
not be possible with terrain or building constraints. In another
embodiment, the mini-POP device 102 can operate with a human in the
loop (HITL) to update the cache contents. HITL implies that a
person will be tasked with manually swapping out the hard drives
with a hard drives with the updated content or adding the content
to the hard drive. This solution may be a relatively high bandwidth
but extremely high latency solution and may only be suitable if the
use cases allow longer times (e.g., hours) to service a cache
miss.
[0047] The WMN 100 may be considered a multi-radio multi-channel
(MRMC) mesh network. MRMC mesh networks are an evolution of
traditional single radio WMNs and a leading contender for
combatting the radio resource contention that has plagued single
radio WMNs and prevents them from scaling to any significant size.
The WMN 100 has multiple devices, each with multi-radio
multi-channel (MRMC) radios. The multiple radios for P2P
connections and N2C connections of the mesh network devices allow
the WMN 100 to be scaled to a significant size, such as 10,000 mesh
nodes. For example, unlike the conventional solutions that could
not effectively scale, the embodiments described herein can be very
large scale, such as a 100.times.100 grid of nodes with 12-15 hops
between nodes to serve content to client consumption devices. The
paths to fetch content files may not be a linear path within the
mesh network.
[0048] The WMN 100 can provide adequate bandwidth, especially
node-to-node bandwidth. For video, content delivery services
recommend a minimum of 900 Kbps for standard definition content and
3.5 Mbps for high definition content. The WMN 100 can provide
higher bandwidths than those recommended for standard definition
and high definition content. Prior solutions found that for a
10,000-node mesh network covering one square kilometer, the upper
bound on inter-node traffic is 221 kbps. The following can impact
bandwidth: forwarding traffic, wireless contention (MAC/PHY), and
routing protocols.
[0049] In some embodiments, the WMN 100 can be self-contained as
described herein. The WMN 100 may be self-contained in the sense
that content resides in, travels through, and is consumed by nodes
in the mesh network without requiring the content to be fetched
outside of the WMN 100. In other embodiments, the WMN 100 can have
mechanisms for content injection and distribution. One or more of
the services 120 can manage the setup of content injection and
distribution. These services (e.g., labeled mesh network control
service) can be hosted by as cloud services, such as on one or more
content delivery service devices. These mechanisms can be used for
injecting content into the network as new content is created or as
user viewing preferences change. Although these injection
mechanisms may not inject the content in real time, the content can
be injected into the WMN 100 via the point-to-point wireless
connection 105 or the HITL process at the mini-POP device 102.
Availability and impact on cost in terms of storage may be relevant
factors in determining which content is to be injected into the WMN
100 and which content is to remain in the WMN 100. A challenge for
traditional mesh network architectures is that this content is high
bandwidth (in the case of video) and so the gateway nodes that
connect the mesh to the larger Internet must be also be high
bandwidth. However, taking a closer look at the use case reveals
that this content, although high bandwidth, does not need to be low
latency. The embodiments of the WMN 100 described herein can
provide distribution of content that is high bandwidth, but in a
manner that does not need low latency.
[0050] In some embodiments, prior to consumption by a node having
an AIV client itself or being wirelessly connected to an AIV client
executing on a client consumption device, the content may be pulled
close to that node. This may involve either predicting when content
will be consumed to proactively move it closer (referred to as
caching) or always having it close (referred to as replication).
Content replication is conceptually straightforward, but may impact
storage requirements and requires apriori knowledge on the
popularity of given titles.
[0051] Another consideration is where and how to store content in
the WMN 100. The WMN 100 can provide some fault tolerance so that a
single mesh node becoming unavailable for failure or reboot has
minimal impact on availability of content to other users. This
means that a single mesh node is not the sole provider of a piece
of content. The WMN 100 can use reliability and availability
mechanisms and techniques to determine where and how to store
content in the WMN 100.
[0052] The WMN 100 can be deployed in an unpredictable environment.
Radio conditions may not be constant and sudden losses of power may
occur. The WMN 100 is designed to be robust to temporary failures
of individual nodes. The WMN 100 can be designed to identify those
failures and adapt to these failures once identified. Additionally,
the WMN 100 can include mechanisms to provide secure storage of the
content that resides within the WMN 100 and prevent unauthorized
access to that content.
[0053] The cloud services 120 of the WMN 100 can include mechanisms
to deal with mesh nodes that become unavailable, adding, removing,
or modifying existing mesh nodes in the WMN 100. The cloud services
120 may also include mechanisms for remote health and management.
For example, there may be a remote health interface, a management
interface, or both to access the mesh nodes for this purpose. The
cloud services 120 can also include mechanisms for securing the WMN
100 and the content that resides in the WMN 100. For example, the
cloud services 120 can control device access, DRM, and node
authentication.
[0054] FIG. 2 is a block diagram of a network hardware device 202
with five radios operating concurrently in a wireless mesh network
200 according to one embodiment. The wireless mesh network 200
includes multiple network hardware devices 202-210. The network
hardware device 202 may be considered a mesh router that includes
four 5 GHz radios for the network backbone for multiple connections
with other mesh routers, i.e., network hardware devices 204-210.
For example, the network hardware device 204 may be located to the
north of the network hardware device 202 and connected over a first
5 GHz connection. The network hardware device 206 may be located to
the east of the network hardware device 202 and connected over a
second 5 GHz connection. The network hardware device 208 may be
located to the south of the network hardware device 202 and
connected over a third 5 GHz connection. The network hardware
device 210 may be located to the west of the network hardware
device 202 and connected over a fourth 5 GHz connection. In other
embodiments, additional network hardware devices can be connected
to other 5 GHz connections of the network hardware device 202. It
should also be noted that the network hardware devices 204-210 may
also connect to other network hardware devices using its respective
radios. It should also be noted that the locations of the network
hardware devices 20-210 can be in other locations that north,
south, east, and west. For example, the network hardware devices
can be located above or below the mesh network device 202, such as
on another floor of a building or house.
[0055] The network hardware device 202 also includes at least one
2.4 GHz connection to serve client consumption devices, such as the
client consumption device 212 connected to the network hardware
device 202. The network hardware device 202 may operate as a mesh
router that has five radios operating concurrently or
simultaneously to transfer mesh network traffic, as well as service
connected client consumption devices. This may require that the
5GLL and 5GLH to be operating simultaneously and the 5GHL and 5GHH
to be operating simultaneously, as described in more detail below.
It should be noted that although the depicted embodiment
illustrates and describes five mesh nodes, in other embodiments,
more than five mesh nodes may be used in the WMN. It should be
noted that FIG. 2 is a simplification of neighboring mesh network
devices for a given mesh network device. The deployment of forty or
more mesh network devices may actually be located at various
directions than simply north, south, east, and west as illustrated
in FIG. 2. Also, it should be noted that here are a limited number
of communication channels available to communicate with neighboring
mesh nodes in the particular wireless technology, such as the
Wi-Fi.RTM. 5 GHz band. The embodiments of the mesh network devices,
such as the directional antennas, can help with isolation between
neighboring antennas that cannot be separated physically given the
limited size the mesh network device.
[0056] FIG. 3 is a block diagram of a mesh node 300 with multiple
radios according to one embodiment. The mesh node 300 includes a
first 5 GHz radio 302, a second 5 GHz radio 304, a third 5 GHz
radio 306, a fourth 5 GHz radio 308, a fifth 5 GHz radio 314, a
sixth 5 GHz radio 316, a 2.4 GHz radio 310, and a cellular radio
312. The first 5 GHz radio 302 creates a first P2P wireless
connection 303 between the mesh node 300 and another mesh node (not
illustrated) in a WMN. The second 5 GHz radio 304 creates a second
P2P wireless connection 305 between the mesh node 300 and another
mesh node (not illustrated) in the WMN. The third 5 GHz radio 306
creates a third P2P wireless connection 307 between the mesh node
300 and another mesh node (not illustrated) in the WMN. The fourth
5 GHz radio 308 creates a fourth P2P wireless connection 309
between the mesh node 300 and another mesh node (not illustrated)
in the WMN. The fifth 5 GHz radio 316 creates a fourth P2P wireless
connection 316 between the mesh node 300 and another mesh node (not
illustrated) in the WMN. The sixth 5 GHz radio 318 creates a fourth
P2P wireless connection 320 between the mesh node 300 and another
mesh node (not illustrated) in the WMN. In some embodiments, the
mesh node includes four 5 GHz radios, in which case the fifth 5 GHz
radio 314 and the sixth 5 GHz radio 318 may be excluded.
[0057] The 2.4 GHz radio 310 creates a N2C wireless connection 311
between the mesh node 300 and a client consumption device (not
illustrated) in the WMN. The cellular radio 312 creates a cellular
connection between the mesh node 300 and a device in a cellular
network (not illustrated). In other embodiments, more than one 2.4
GHz radios may be used for more N2C wireless connections.
Alternatively, different number of 5 GHz radios may be used for
more or less P2P wireless connections with other mesh nodes. In
other embodiments, multiple cellular radios may be used to create
multiple cellular connections.
[0058] In another embodiment, a system of devices can be organized
in a WMN. The system may include a single ingress node for ingress
of content files into the wireless mesh network. In one embodiment,
the single ingress node is a mini-POP device that has attached
storage device(s). The single ingress node may optionally include a
point-to-point wireless connection, such as a microwave
communication channel to a node of the CDN. The single ingress node
may include a point-to-point wireless link to the Internet (e.g., a
server device of the CDN) to access content files over the
Internet. Alternatively to, or in addition to the point-to-point
wireless link, the single ingress node may include a wired
connection to a storage device to access the content files stored
on the storage device. Multiple network hardware devices are
wirelessly connected through a network backbone formed by multiple
P2P wireless connections. These P2P wireless connections are
wireless connections between different pairs of the network
hardware devices. The P2P wireless connections may be a first set
of WLAN connections that operate at a first frequency of
approximately 5.0 GHz. The multiple network hardware devices may be
wirelessly connected to one or more client consumption devices by
one or more N2C wireless connections. Also, the multiple network
hardware devices may be wirelessly connected to a mesh network
control services (MNCS) device by cellular connections. Each
network hardware device includes a cellular connection to a MNCS
service hosted by a cloud computing system. The cellular
connections may have lower bandwidths than the point-to-point
wireless link.
[0059] The system includes a first network hardware device
wirelessly connected to a first client consumption device by a
first node-to-client (N2C) wireless connection and a second network
hardware device wirelessly connected to the single ingress node.
The first network hardware device can wirelessly connect to a first
client consumption device over a first N2C connection. The N2C
wireless connection may be one of a second set of one or more WLAN
connections that operate at a second frequency of approximately 2.4
GHz. During operation, the first network hardware device may
receive a first request for a first content file from the first
client consumption device over the first N2C connection. The first
network device sends a second request for the first content file to
the second network hardware device through the network backbone via
a first set of zero or more intervening network hardware devices
between the first network hardware device and the second network
hardware device. The first network device receives the first
content file from the first network hardware device through the
network backbone via the first set of zero or more intervening
network hardware devices and sends the first content file to the
first client consumption device over the first N2C connection. In a
further embodiment, the first network hardware device includes
another radio to wirelessly connect to a MNCS device by a cellular
connection to exchange control data.
[0060] In a further embodiment, the first network hardware device
is further to receive a third request for a second content file
from a second client consumption device connected to the first
network hardware device over a second N2C connection between the
first network hardware device and the second client consumption
device. The first network hardware device sends a fourth request
for the second content file stored at a third network hardware
device through the network backbone via a second set of zero or
more intervening network hardware devices between the first network
hardware device and the third network hardware device. The first
network hardware device receives the second content file from the
third network hardware device through the network backbone via the
second set of zero or more intervening network hardware devices.
The first network hardware device sends the second content file to
the second client consumption device over the second N2C
connection.
[0061] In one embodiment, the zero or more intervening network
hardware devices of the first set are not the same as the zero or
more intervening network hardware devices of the second set. In
some embodiments, a path between the first network hardware device
and the second network hardware device could include zero or more
hops of intervening network hardware devices. In some cases, the
path may include up to 12-15 hops within a mesh network of
100.times.100 network hardware devices deployed in the WMN. In some
embodiments, a number of network hardware devices in the WMN is
greater than fifty. The WMN may include hundreds, thousands, and
even tens of thousands of network hardware devices.
[0062] In a further embodiment, the first network hardware device
receive the fourth request for the second content file from a
fourth network hardware device through the network backbone via a
third set of zero or more intervening network hardware devices
between the first network hardware device and the fourth network
hardware device. The first network hardware device sends the second
content file to the fourth network hardware device through the
network backbone via the third set of zero or more intervening
network hardware devices.
[0063] In some embodiments, the first network hardware device
determines whether the first content file is stored in memory of
the first network hardware device. The memory of the first network
hardware device may be volatile memory, non-volatile memory, or a
combination of both. When the first content file is not stored in
the memory or the storage of the first network hardware device, the
first network hardware device generates and sends the second
request to a first network hardware device of the first set.
Intervening network hardware devices can make similar
determinations to locate the first content file in the WMN. In the
event that the first content file is not stored in the second
network hardware device or any intervening nodes, the second
network hardware device can request the first content file from the
mini-POP device, as described herein. When the mini-POP device does
not store the first content file, the mini-POP can take action to
obtain the first content file, such as requesting the first content
file from a CDN over a point-to-point link. Alternatively, the
human in the loop process can be initiated as described herein.
[0064] In a further embodiment, the second network hardware device
receives the second request for the first content file and
retrieves the first content file from the single ingress node when
the first content file is not previously stored at the second
network hardware device. The second network hardware device sends a
response to the second request with the first content file
retrieved from the single ingress node. The second network hardware
device may store a copy of the first content file in memory of the
second network hardware device for a time period.
[0065] In another embodiment, the single ingress node receives a
request for a content file from one of the multiple network
hardware devices over a P2P wireless connection. The request
originates from a requesting consumption device. It should be noted
that a video client can be installed on the client consumption
device, on the network hardware device, or both. The single ingress
node determines whether the content file is stored in a storage
device coupled to the single ingress node. The single ingress node
generates and sends a first notification to the requesting one of
the network hardware devices over the P2P wireless connection when
the content file is not stored in the storage device. The first
notification includes information to indicate an estimated delay
for the content file to be available for delivery. The single
ingress node generates and sends a second notification to an
operator of the first network hardware device. The second
notification includes information to indicate that the content file
has been requested by the requesting client consumption device. In
this embodiment, the notifications can be pushed to the appropriate
recipients. In another embodiment, an operator can request which
content files had been requested in the WMN and not serviced. This
can initiate the ingress of the content file into the WMN, even if
with a longer delay.
[0066] In some embodiments, the mini-POP device is coupled to a
storage device to store the content files as original content files
for the wireless mesh network. A point-to-point wireless link may
be established between the mini-POP device and a CDN device. In
another embodiment, the mini-POP device is coupled to a node of a
content delivery network (CDN) via a microwave communication
channel.
[0067] In a further embodiment, the second network hardware device
can wirelessly connect to a third network hardware device over a
second P2P connection. During operation, the third network hardware
device may receive a third request for a second content file from a
second client consumption device over a second N2C connection
between the third network hardware device and the second client
consumption device. The third network hardware device sends a
fourth request for the second content file to the second network
hardware device over the second P2P connection. The third network
hardware device receives the second content file from the second
network hardware device over the second P2P connection and sends
the second content file to the second client consumption device
over the second N2C connection.
[0068] In another embodiment, the first network hardware device
receives the fourth request for the second content file from the
third network hardware device. The second network hardware device
determines whether the second content file is stored in memory of
the second network hardware device. The second network hardware
device sends a fifth request to the first network hardware device
over the first P2P connection and receive the second content file
over the first P2P connection from the first network hardware
device when the second content file is not stored in the memory of
the second network hardware device. The second network hardware
device sends the second content file to the third network hardware
device over the second P2P connection.
[0069] In another embodiment, the second network hardware device
may wirelessly connect to a third network hardware device over a
second P2P connection. During operation, the third network hardware
device may receive a third request for the first content file from
a second client consumption device over a second N2C connection
between the third network hardware device and the second client
consumption device. The third network hardware device sends a
fourth request for the first content file to the second network
hardware device over the second P2P connection. The third network
hardware device receives the first content file from the first
network hardware device over the second P2P connection and sends
the first content file to the second client consumption device over
the second N2C connection.
[0070] In another embodiment, the first network hardware device
receives a request for a content file from one of the network
hardware devices over one of the P2P wireless connections. The
request is from a requesting client consumption device connected to
one of the multiple network hardware devices. The first network
hardware device determines whether the content file is stored in
the storage device. The first network hardware device generates and
sends a first notification to the one of the network hardware
devices over the one of the P2P wireless connections when the
content file is not stored in the storage device. The first
notification may include information to indicate an estimated delay
for the content file to be available for delivery. The first
network hardware device generates and sends a second notification
to an operator of the first network hardware device. The second
notification may include information to indicate that the content
file has been requested by the requesting client consumption
device.
[0071] In a further embodiment, the P2P wireless connections are
WLAN connections that operate in a first frequency range and the
N2C connections are WLAN connections that operate in a second
frequency range. In another embodiment, the P2P wireless
connections operate at a first frequency of approximately 5.0 GHz
and the N2C connections operate at a second frequency of
approximately 2.4 GHz.
[0072] In some embodiments, at least one of the network hardware
devices is a mini-POP) node and a point-to-point wireless link is
established between the mini-POP device and a POP device of an ISP.
In one embodiment, the point-to-point wireless link is a microwave
link (e.g., directional microwave link) between the mini-POP device
and the CDN device. In another embodiment, the mini-POP device
stores an index of the content files store in attached storage
devices.
[0073] In some embodiments, a mesh network architecture includes
multiple mesh nodes organized in a self-contained mesh network. The
self-contained mesh network may be self-contained in the sense that
content resides in, travels through, and is consumed by nodes in
the mesh network without requiring the content to be fetched
outside of the mesh network. Each of the mesh nodes includes a
first radio for inter-node communications with the other nodes on
multiple P2P channels, a second radio for communications with
client consumption devices on N2C channels. The mesh network
architecture also includes a mini-POP device including a radio for
inter-connection communications with at least one of the mesh nodes
on a P2P channel. The mesh network architecture also includes a
storage device coupled to the mini-POP, the storage device to store
content files for distribution to a requesting client consumption
device. The mini-POP device may be the only ingress point for
content files for the self-contained mesh network. The storage
devices of the mini-POP device may be internal drives, external
drives, or both. During operation, a first node of the mesh nodes
includes a first radio to wirelessly connect to a requesting client
consumption device via a first N2C channel to receive a first
request for a content file directly from the requesting client
consumption device via a first N2C channel between the first node
and the requesting client consumption device 1. A second radio of
the first node sends a second request for the content file to a
second node via a first set of zero or more intervening nodes
between the first node and the second node to locate the content
file within the self-contained mesh network. The second radio
receives the content file from the second node in response to the
request. The first radio sends the content file to the requesting
client consumption device via the first N2C channel. The first node
determines a location of the content file within the self-contained
mesh network and sends a second request for the content file via a
second P2P channel to at least one of the mini-POP or a second
node, the second request to initiate delivery of the content file
to the requesting client consumption device over a second path
between the location of the content file and the requesting client
consumption device.
[0074] In another embodiment, the first node stores a copy of the
content file in a storage device at the first node. The first node
receives a third request for the content file directly from a
second client consumption device via a second N2C channel between
the first node and the second client consumption device. The first
node sends the copy of the content file to the second client
consumption device via the second N2C channel in response to the
third request.
[0075] In a further embodiment, the first node receives the content
file via the second P2P channel in response to the second request
and sends the content file to the requesting client consumption
device via the first N2C channel or the first P2P channel in
response to the first request. In some embodiments, the second path
and the first path are the same. In a further embodiment, the first
node includes a third radio to communicate control data over a
cellular connection between the first node and a mesh network
control service (MNCS) device.
[0076] In one embodiment, the second radio can operate with
2.times.2 MIMO with maximum 40 MHz aggregation. This may result in
per radio throughput of not more than 300 Mbps in 5 GHz and 150
Mbps in 2.4 GHz. Even with 6 radios (4.times.5 GHz and 1.times.2.4
GHz and 1.times.WAN), the peak physical layer throughput will not
need to be more than 1.4 Gbps. A scaling factor of 1.4 may be used
to arrive at a CPU frequency requirement. This implies the total
processing clock speed in the CPU should not be less than 1.96 GHz
(1.4.times.1.4=1.96 GHz). For example, the Indian ISM band has a
requirement of 23 dBm EIRP. Since the WMN 100 needs to function
under conditions where the mesh routers communicate with each other
between homes, the propagation loss through multiple walls and over
distances between homes, the link budget does not support
sensitivity requirements for 802.11ac data rates. The per-node
throughput may be limited to 300 Mbps per link--peak PHY rate.
[0077] In another embodiment, a system includes a POP device having
access to content files via at least one of data storage coupled to
the POP device or a first point-to-point connection to a first
device of an ISP. The system also includes multiple mesh nodes,
organized in a WMN, and at least one of the mesh nodes is
wirelessly coupled to the POP device. The WMN is a mesh topology in
which the multiple mesh nodes cooperate in distribution of the
content files to client consumption devices that do not have access
to reliable access to the server device of the CDN or in an
environment of limited connectivity to broadband infrastructure. A
first node of the multiple mesh nodes is a multi-radio,
multi-channel (MRMC) device that includes multiple P2P connections
to form parts of a network backbone in which the first node
wireless connects to other mesh nodes via a first set of WLAN
channels reserved for inter-node communication. The first node also
includes one or more N2C connections to wireless connect to one or
more of the client consumption devices connected to the WMN via a
second set of WLAN channels reserved for serving the content files
to the client consumption devices. The first node may also include
a cellular connection to wireless connect to a second device of the
CDN. The second device may be part of a cloud computing system and
may host a mesh network control service as described herein. It
should be noted that the first point-to-point connection is higher
bandwidth than the cellular connection.
[0078] FIG. 4 is a block diagram of a mesh network device 400
according to one embodiment. The mesh network device 400 may be one
of many mesh network devices organized in a WMN (e.g., WMN 100).
The mesh network device 400 is one of the nodes in a mesh topology
in which the mesh network device 400 cooperates with other mesh
network devices in distribution of content files to client
consumption devices in an environment of limited connectivity to
broadband Internet infrastructure, as described herein. That is,
the client consumption devices do not have Internet connectivity.
The mesh network device 400 may be the mini-POP device 102 of FIG.
1. Alternatively, the mesh network device 400 may be any one of the
mesh network devices 104-110 of FIG. 1. In another embodiment, the
mesh network device 400 is any one of the network hardware devices
202-210 of FIG. 2. In another embodiment, the mesh network device
400 is the mesh node 300 of FIG. 3.
[0079] The mesh network device 400 includes a system on chip (SoC)
402 to process data signals in connection with communicating with
other mesh network devices and client consumption devices in the
WMN. The SoC 402 includes a processing element (e.g., a processor
core, a central processing unit, or multiple cores) that processes
the data signals and controls the radios to communicate with other
devices in the WMN. In one embodiment, the SoC 402 is a dual core
SoC, such as the ARM A15 1.5 GHz with hardware network
acceleration. The SoC 402 may include memory and storage, such as 2
GB DDR RAM and 64 GB eMMC coupled to the SoC 402 via external HDD
interfaces (e.g., SATA, USB3, or the like). The SoC 402 may include
multiple RF interfaces, such as a first interface to the first RF
radio 404 (e.g., HSCI interface for cellular radio (3G)), a second
interface to the WLAN 2.4 GHz radio 406, a third interface to the
WLAN 5 GHz radio 408, and multiple interfaces to the WLAN 5 GHz
radios, such as on a PCIe bus. Alternatively, the SoC 402 includes
as many digital interfaces for as many radios there are in the mesh
network device 400. In one embodiment, the SoC 402 is the IPQ8064
Qualcomm SoC or the IPQ4029 Qualcomm SoC. Alternatively, other
types of SoCs may be used, such as the Annapurna SoC, or the like.
Alternatively, the mesh network device 400 may include an
application processor that is not necessarily considered to be a
system on a chip.
[0080] The mesh network device 400 may also include memory and
storage. For example, the mesh network device 400 may include SSD
64 GB 428, 8 GB Flash 430, and 2 GB 432. The memory and storage may
be coupled to the SoC 402 via one or more interfaces, such as USB
3.0, SATA, or SD interfaces. The mesh network device 400 may also
include a single Ethernet port 444 that is an ingress port for
Internet Protocol (IP) connection. The Ethernet port 444 is
connected to the Ethernet PHY 442, which is connected to the SoC
402. The Ethernet port 444 can be used to service the mesh network
device 400. Although the Ethernet port 444 could provide wired
connections to client devices, the primary purpose of the Ethernet
port 444 is not to connect to client devices, since the 2.4 GHz
connections are used to connect to clients in the WMN. The mesh
network device 400 may also include one or more debug ports 446,
which are coupled to the SoC 402. The memory and storage may be
used to cache content, as well as store software, firmware or other
data for the mesh network device 400.
[0081] The mesh network device 400 may also include a power
management and charging system 434. The power management and
charging system 434 can be connected to a power supply 436 (e.g., a
240V outlet, a 120V outlet, or the like). The power management and
charging system 434 can also connect to a battery 438. The battery
438 can provide power in the event of power loss. The power
management and charging system 434 can be configured to send a SOS
message on power outage and backup system state. For example, the
WLAN radios can be powered down, but the cellular radio can be
powered by the battery 438 to send the SOS message. The battery 438
can provide limited operations by the mesh network device 400, such
as for 10 minutes before the entire system is completely powered
down. In some cases, power outage will likely affect a geographic
area in which the mesh network device 400 is deployed (e.g., power
outage that is a neighborhood wide phenomenon). The best option may
be to power down the mesh network device 400 and let the cloud
service (e.g., back end service) know of the outage in the WMN. The
power management and charging system 434 may provide a 15V power
supply up to 21 watts to the SoC 402. Alternatively, the mesh
network device 400 may include more or less components to operate
the multiple antennas as described herein.
[0082] The mesh network device 400 includes a first radio frequency
(RF) radio 404 coupled between the SoC 402 and an antenna 418
adapted to be connected to a radio that transmits and receives on a
cellular frequency. The first RF radio 404 supports cellular
connectivity using the antenna 418. In one embodiment, the first RF
radio 404 is a wireless wide area network (WWAN) radio and the
antenna 418 is a WWAN antenna. WWAN is a form of wireless network
that is larger in size than a WLAN and uses different wireless
technologies. The wireless network can deliver data in the form of
telephone calls, web pages, texts, messages, streaming content, or
the like. The WWAN radio may use mobile telecommunication cellular
network technologies, such as LTE, WiMAX (also called wireless
metropolitan area network (WMAN)), UTMS, CDMA2000, GSM, cellular
digital packet data (CDPD), Mobitex, or the like, to transfer
data.
[0083] In one embodiment, the antenna 418 may include a structure
that includes a primary WAN antenna and a secondary WAN antenna.
The first RF radio 404 may be a wireless wide area network (WWAN)
radio and the antenna 418 is a WWAN antenna. The first RF radio 404
may include a modem to cause the primary WAN antenna, the secondary
WAN antenna, or both to radiate electromagnetic energy in the 900
MHz band and 1800 MHz band for the 2G specification, radiate
electromagnetic energy in the B1 band and the B8 band for the 3G
specification, and radiate electromagnetic energy for the B40 band.
The modem may support Cat3 band, 40 TD-LTE, UMTS: Band 1, Band 8,
and GSM: 900/1800. The modem may or may not support CDMA. The
cellular modem may be used for diagnostics, network management,
down time media caching, meta data download, or the like.
Alternatively, the first RF radio 404 may support other bands, as
well as other cellular technologies. The mesh network device 400
may include a GPS antenna and corresponding GPS radio to track the
location of the mesh network device 400, such as moves between
homes. However, the mesh network device 400 is intended to be
located inside a structure, the GPS antenna and radio may not be
used in some embodiments.
[0084] The mesh network device 400 includes a first set of wireless
local area network (WLAN) radios 406, 408 coupled between the SoC
402 and dual-band omnidirectional antennas 420. A first WLAN radio
406 may support WLAN connectivity in a first frequency range using
one of the dual-band omnidirectional antennas 420. A second WLAN
radio 408 may support WLAN connectivity in a second frequency range
using one of the dual-band omnidirectional antennas 420. The
dual-band omnidirectional antennas 420 may be two omnidirectional
antennas for 2.4 GHz. The directional antennas 422 may be six
sector directional antennas for 5 GHz with two antennas at
orthogonal polarizations (horizontal/vertical) or arranged for
cross-polarization in each sector. These can be setup with 45
degree 3 dB beam width with 11 dB antenna gain. The dual-band
omnidirectional antennas 420 and the directional antennas 422 can
be implemented as a fully switchable antenna architecture
controlled by micro controller 426. For example, each 5 GHz radio
can choose any 2 sectors (for two 2.times.2 MU-MIMO streams). In
additional embodiments, one or more of the dual-band
omnidirectional antennas 420 may each be combined with the antenna
418 on the same PCB and may share a common ground (FIGS. 7A-7B),
which may be referred to herein as a combination omnidirectional
antenna.
[0085] The mesh network device 400 includes a second set of WLAN
radios 410-416 coupled between the SoC 402 and antenna switching
circuitry 424. The second set of WLAN radios 410-416 support WLAN
connectivity in the second frequency range using a set of
directional antennas 422. The four WLAN radios are exemplary, as
there may be more than four WLAN radios to correspond to additional
directional antennas 422. The second set of WLAN radios 410-416 is
operable to communicate with the other mesh network devices of the
WMN. Where there are more directional antennas 422 than radios,
each of the second set of WLAN radios 410-416 may be directly
connected to a respective one of the directional antennas, and the
antenna switching circuitry 424 may provide switching hardware and
software to switch one of the WLAN radios to a directional antenna
that is not directly connected to one of the radios. For example,
the antenna switching circuitry 424 may include one or more switch,
each switch being coupled between a directional antenna and one of
the WLAN radios to which the directional antenna is not normally
directly connected.
[0086] The antenna switching circuitry 424 is coupled to a micro
controller 426. The micro controller 426 controls the antenna
switching circuitry 424 to select different combinations of
antennas for wireless communications between the mesh network
device 400 and the other mesh network devices, the client
consumption devices, or both. For example, the micro controller 426
can select different combinations of the set of directional
antennas 422. In one embodiment, the SoC 402 runs a mesh selection
algorithm to decide which communication path to use for any
particular communication and instructs, or otherwise commands, the
micro controller 426 to select the appropriate communication path
between a selected radio and a selected antenna. Alternatively, the
micro controller 426 can receive indications from the SoC 402 of
which radio is to be operating and the micro controller 426 can
select an appropriate communication path between a radio (or a
channel of the radio) and an appropriate antenna.
[0087] In another embodiment, a filter switch bank is coupled
between the antenna switching circuitry 424 and the second set of
WLAN radios 410-416. In another embodiment, the filter switch bank
can be implemented within the antenna switching circuitry 424.
[0088] In the depicted embodiment, the first set of WLAN radios
include a 2.times.2 2.4 GHz MIMO radio 406 and a first 2.times.2 5
GHz MIMO radio 408. The second set of WLAN radios includes a second
2.times.2 5 GHz MIMO radio 410 ("5GLL"), a third 2.times.2 5 GHz
MIMO radio 412 ("5GLH"), a fourth 2.times.2 5 GHz MIMO radio 414
("5GHL"), and a fifth 2.times.2 5 GHz MIMO radio 416 ("5GHH"). The
dual-band omnidirectional antennas 420 may include a first
omnidirectional antenna and a second omnidirectional antenna (not
individually illustrated in FIG. 4). The set of directional
antennas 422 may include antennas of any combination of vertical
orientation, horizontal orientation, or angled polarization. In one
embodiment, there may be six antennas, each being a set of
cross-polarized antennas as will be discussed in additional
detail.
[0089] In one embodiment, the mesh network device 400 can handle
antenna switching in a static manner. The SoC 402 can perform
sounding operations with the WLAN radios to determine a switch
configuration. Switching may not be done on a per packet basis or
at a packet level. The static switch configuration can be evaluated
a few times a day by the SoC 402. The SoC 402 can include the
intelligence for switching decision based on neighbor sounding
operations done by the SoC 402. The micro controller 426 can be
used to program the antenna switching circuitry 424 (e.g., switch
matrix) since the mesh network device 400 may be based on CSMA-CA,
not TDMA. Deciding where the data will be coming into the mesh
network device 400 is not known prior to receipt, so dynamic
switching may not add much benefit. It should also be noted that
network backbone issues, such as one of the mesh network devices
becoming unavailable, may trigger another neighbor sounding process
to determine a new switch configuration. Once the neighbor sounding
process is completed, the mesh network device 400 can adapt a beam
patter to be essentially fixed since the mesh network devices are
not intended to move once situated.
[0090] FIG. 5A illustrates a multi-radio, multi-channel (MRMC)
network device 500 according to one embodiment. The MRMC network
device 500 may include a metal housing 502 that is elongated, e.g.,
has a height greater than a width, and that includes a number of
sides that make up a perimeter of the metal housing. The metal
housing 502 may be made of stainless steel or some other metal. In
the depicted embodiment, the metal housing 502 has six sides, a
first side, a second side, a third side, and a fourth side that are
rectangular and form a length of the metal housing 502, a fifth
side at a top of the metal housing, and a sixth side at a bottom of
the metal housing 502. Additional or fewer sides are envisioned.
Each of the fifth side and the sixth side may be square.
[0091] With further reference to FIG. 5A, the metal housing may
form a number of chambers (e.g., isolation chambers) that
correspond to respective sides and open to the outside of the metal
housing. For example, the metal housing 502 may include a first
metal section 504 that forms a first chamber, a second metal
section 506 that forms a second chamber, a third metal section 508
that forms a third chamber, and a fourth metal section 510 that
forms a fourth chamber at the four rectangular sides of the metal
housing, a fifth metal section 512 that forms a top chamber at the
top of the metal housing, and a sixth metal section 514 that forms
a bottom chamber at the bottom of the metal housing 502. Each
chamber may be formed from multiple reflective sidewalls, to
reflect electromagnetic energy away from the metal housing, and
that also provide electromagnetic isolation from other ambient
electromagnetic waves.
[0092] In various embodiments, for example, four sidewalls extend
from a back wall to form each chamber that is oriented to an
outside of the metal housing 502. The four sidewalls are made of
reflective metal to directionally reflect electromagnetic energy.
Use of more than four sidewalls is envisioned in alternative
embodiments. As depicted, each of the metal sections 504, 506, 508,
and 510 may form a chamber shaped as a truncated triangular prism
structure, which is defined by a back wall and four sidewalls. The
four sidewalls may include two rectangular sidewalls each angled
from a long edge of the back wall towards a nearest intersection of
two sides of the metal housing, a top sidewall located between the
two rectangular sidewalls and the back wall at a top of the
chamber, and a bottom sidewall located between the two rectangular
sidewalls and the back wall at a bottom of the chamber. The area
near each back wall may define a recessed region that is narrower
than a mouth of each chamber. Furthermore, the fifth metal section
510 may form the top chamber and the sixth metal section 512 may
form the bottom chamber. Each of the top chamber and the bottom
chamber may be shaped as a truncated pyramid structure defined by a
back wall and four angled sidewalls.
[0093] In various embodiments, an antenna may be disposed within
each chamber, e.g., coupled to the back wall of the chamber. For
example, a first antenna 521 may be disposed in the first chamber,
a second antenna 523 may be disposed within the second chamber, a
third antenna (not visible) may be disposed within the third
chamber, and a fourth antenna (not visible) may be disposed within
the fourth chamber. Furthermore, a fifth antenna 529 may be
disposed within the top chamber and a sixth antenna (not
illustrated) may be disposed within the bottom chamber. Each
chamber may electrically isolate the antenna of the chamber from
the antenna of a different chamber, so that each antenna generates
a separate radiation pattern in one of the six different directions
of the MRMC network device 500, as shown in FIG. 5B.
[0094] Each of the first, second, third, and fourth antennas may be
rectangular in shape, formed on a printed circuit board (PCB) (such
as a microstrip PCB), and may each be an antenna pair, such as a
pair of phased array patch antennas. Each of the fifth and sixth
antennas may be square in shape, formed on a separate PCB, and also
may each be an antenna pair, such as a pair phased array patch
antennas. The patch elements (not visible) of each phased array
patch antenna may be diamond-shaped. In various embodiments, the
first antenna 521 further includes parasitic elements 524, 526,
528, and 530 retained at a predetermined distance from each
respective diamond-shaped patch element, to act as a parasitic
antenna element within the phased array patch antenna. In one
embodiment, the predetermined distance is a gap of about 3 mm,
although more or less distance may also be appropriate. In one
embodiment, each parasitic element may also be diamond-shaped to
correspond to the diamond-shaped patch elements and may have a
first surface area that is at least 25% larger than a second
surface area of a corresponding patch element. In various
embodiments, the parasitic elements are planar metal members, also
be diamond-shaped, and are retained at the predetermined distance
by way of a non-conductive material such as a dielectric. Various
materials have different dielectric constants, with the materials
having a dielectric constant closest to 1.0 (that of air) being
preferred for electromagnetic operation but not necessarily for
cost. Use of different materials is mentioned hereinafter only by
way of example of such dielectric materials.
[0095] The MRMC network device 500 may further include a first
combination omnidirectional antenna 540 and a second combination
omnidirectional antenna 545, each of which may include the antenna
418 and the dual-band omnidirectional antenna 420 that share a
common ground (discussed in more detail with reference to FIG. 4).
The first combination omnidirectional antenna 540 and the second
combination omnidirectional antenna 545 may be attached to top
sidewalls of adjacent chambers, e.g., to the top sidewall of the
third chamber formed by the third metal section 508 and to the top
sidewall of the fourth chamber formed by the fourth metal section
510, respectively.
[0096] FIG. 5B illustrates a set of radiation patterns 550 of the
MRMC network device 500 of FIG. 5A according to one embodiment.
With additional reference to FIG. 5A, a number of radios may also
be located on a main circuit board (1402 in FIG. 14) located within
an inner chamber of the metal housing 502, e.g., located between
the six metal sections 504, 506,508, 510, 512, and 514. Each
antenna may be coupled to a separate radio, and in alternative
embodiments, some antennas share a radio via switching circuitry as
previously discussed with reference to FIG. 4. Each radio may be
operable to cause the antenna to which it is coupled to radiate
electromagnetic energy outwardly away from the metal housing 502.
Due to the structure of the metal section that defines each
chamber, the chambers may each reflect the electromagnetic energy
in a different direction, e.g., away from the metal housing in the
four directions corresponding to the four sides, out the top, and
out the bottom of the metal housing 502 as illustrated in FIG. 5B,
effectively providing spherical radiation coverage of
electromagnetic energy.
[0097] More specifically, the set of radiation patterns 550 may
include a first radiation pattern 554 out of the first metal
section 504, a second radiation pattern 556 out of the second metal
section 506, a third radiation pattern 558 out of the third metal
section 508, a fourth radiation pattern 560 out of the fourth metal
section 510, a fifth radiation pattern 562 out of the fifth metal
section 512, and a sixth radiation pattern 564 out of the sixth
metal section 514. In this way, the chambers formed by these metal
sections may play a role with directing the radiation pattern of
each respective antenna, and also to isolate each respective
antenna from both the radiation patterns of other antennas of the
MRMC network device 500 and ambient electromagnetic waves or
interference.
[0098] FIG. 6A illustrates a phased array patch antenna 621 on a
printed circuit board (PCB) 622 according to one embodiment. The
PCB 622 may be rectangular and fit within the recessed region of
any of the chambers formed by the metal sections 504, 506, 508, and
510. The phased array patch antenna 621 may be similar to the first
antenna 521 illustrated in FIG. 5A, but without the parasitic
elements (for clarity). The phased array patch antenna 621 may
include a series of patch elements, e.g., in this case four patch
elements: a first patch element 624, a second patch element 626, a
third patch element 628, and a fourth patch element 630. The four
patch elements is aligned along a first axis and is dual fed with
two sets of metal lines, a first set containing a first RF feed 641
and a second set containing a second RF feed 645. Each of the first
RF feed 641 and the second RF feed 645 is coupled to a radio on the
main circuit board.
[0099] More specifically, the four patch elements may be conductive
and electrically connected in parallel with a first set and a
second set of metal lines. The four patch elements may be coupled
to a ground (not illustrated) through the back of the PCB 622,
which will be discussed in more detail. The first set of metal
lines, located on a first side of the four patch elements, includes
a first metal line 623 to connect the first patch element 624 and
the second patch element 626 (e.g., a first pair of patch
elements), and a second metal line 625 to connect the third patch
element 628 and the fourth patch element 630 (e.g., a second pair
of patch elements). A third metal line 627 connects the first metal
line 623 and the second metal line 625 together, and the first RF
feed 641 may be disposed approximately at a center of the third
metal line 627.
[0100] The second set of metal lines, located on a second side of
the four patch elements, includes a fourth metal line 633 to
connect the first patch element 624 and the second patch element
626, and a fifth metal line 635 to connect the third patch element
628 and the fourth patch element 630. A sixth metal line 637 may
connect the fourth metal line 633 and the fifth metal line 635
together, and the second RF feed 645 may be disposed approximately
at a center of the fifth metal line 635.
[0101] More specifically, the first set of metal lines (along the
left of the four patch elements) and the four patch elements form a
first antenna that radiates electromagnetic energy with a first
polarization pattern of approximately a positive 45 degrees and the
second set of metal lines (along the right of the patch elements)
and the four patch elements form a second antenna that radiates
electromagnetic energy with a second polarization pattern at
approximately a negative 45 degrees, which together cumulatively
form a cross-polarization radiation pattern. The combination of the
first antenna and the second antenna provides full benefits of a
multiple input multiple output (MIMO) antenna, although other
single input and single output antennas may also be deployed within
each chamber. By transmitting and receiving on dual-channels and
dual-streams provided by MIMO architecture, throughput may be
higher and a lower envelope correlation coefficient (ECC) is
achievable, which provides better quality and stronger simultaneous
radiation patterns of the co-located first antenna and second
antenna.
[0102] Because the metal housing 502 is taller than wide and the
PCB 622 is elongated along the taller side, the cross-polarization
radiation pattern that is created is relatively flat, e.g., shaped
like a fin. For example, the length (L.sub.1) may be substantially
longer than the width (W.sub.1) and the center-to-center distance
(D.sub.1) between the two sets of patch elements may be sized to
reduce amount of gain drop off. In one embodiment, by way of
example, the length may be 166 mm, the width 34 mm, and the
distance between the two sets of patch elements may be 40 mm. The
center-to-center distance (D.sub.1) may, for example, be sized to
less than the length of one wavelength of the frequency of the
electromagnetic radiation emitted by the phased array patch antenna
621.
[0103] With still more specificity as to the first set of metal
lines, being exemplary of also the second set of metal lines, the
first metal line 623 includes multiple portions: a first portion
extending from the first patch element 624 in a first direction to
a first end; a second portion extending from the first end in a
second direction to a second end; and a third portion extending
from the second end in a third direction to the second patch
element 626. The second portion may taper from the first end and
the second end to a first center of the second portion, and the
first end and the second end may each include a clipped corner. The
second metal line 625 includes multiple portions: a fourth portion
extending from the third patch element 628 in the first direction
to a third end; a fifth portion extending from the third end in the
second direction to a fourth end; and a sixth portion extending
from the fourth end in the third direction to the fourth patch
element 630. The fifth portion may taper from the third end and the
fourth end to a second center of the fifth portion, and the third
end and the fourth end may each include a clipped corner. A third
metal line 627 includes multiple portions: a seventh portion
extending from the first center of the second portion in the first
direction to a fifth end; an eighth portion extending from the
fifth end in the second direction to a sixth end; and a ninth
portion extending from the sixth end in the third direction to the
second center of the fifth portion. The eighth portion may taper
from the fifth end and the sixth end to a third center of the
eighth portion, and each of the fifth end and the sixth end may
include a clipped corner. The first RF feed 641 is disposed at
approximately the third center of the eighth portion, and a first
radio is coupled to the first RF feed 641.
[0104] The detailed description of the first set of metal lines
(e.g., the first metal line 623, the second metal line 625, and the
third metal line 627) applies equally to the second set of metal
lines (e.g., the fourth metal line 633, fifth metal line 635, and
sixth metal line 637), which are disposed symmetrically at the
right sides of the four patch elements 624, 626, 628, and 630.
[0105] FIG. 6B illustrates a phased array patch antenna 648 on a
PCB 652 according to another embodiment. The PCB 622 may be
rectangular and fit within the recessed region of any of either of
the top chamber formed by the fifth metal section 512 or the bottom
chamber formed by the sixth metal section 514. The phased array
patch antenna 648 may be similar to the first antenna 521 of FIG.
5A configured with four patch elements. Fewer or more patch
elements are envisioned depending on the size of the MRMC network
device 500. The phased array patch antenna 648 may therefore
include: a first patch element 654, a second patch element 656 (or
a first set of patch elements), a third patch element 658, and a
fourth patch element 660 (or a second set of patch elements). The
first patch element 654 and the second patch element 656 are
aligned along a first axis, and the third patch element 658 and the
fourth patch element 660 are aligned along a second axis parallel
to the first axis. The first pair and second pair of patch elements
are dual-fed with two sets of metal lines, a first set containing a
first RF feed 671 and a second set containing a second RF feed 675.
Each of the first RF feed 671 and the second RF feed 675 is coupled
to a radio on the main circuit board, e.g., to a second radio.
[0106] The four patch elements may be conductive and electrically
connected in parallel with a first set and a second set of metal
lines. The four patch elements may be coupled to a ground (not
illustrated) through the back of the PCB 652, which will be
discussed in more detail. The first set of metal lines, located on
a first side of the four patch elements, includes a first metal
line 653 to connect the first patch element 654 and the second
patch element 656 (e.g., a first set of patch elements), and a
second metal line 655 to connect the third patch element 658 and
the fourth patch element 660 (e.g., a second set of patch
elements). A third metal line 657 connects the first metal line 653
and the second metal line 655 together, and includes a first RF
feed 671 that may be disposed approximately at a center of the
third metal line 657.
[0107] The second set of metal lines, located on a second side of
the four patch elements, includes a fourth metal line 663 to
connect the first patch element 654 and the second patch element
656, and a fifth metal line 665 to connect the third patch element
658 and the fourth patch element 660. A sixth metal line 667
connects the fourth metal line 663 and the fifth metal line 665
together, and includes a second RF feed 675 that may be disposed
approximately at a center of the sixth metal line 667. The first RF
feed 671 may feed a first patch antenna and the second RF feed 675
may feed a second patch antenna, which cumulatively produce a
cross-polarization radiation pattern.
[0108] More specifically, the first set of metal lines (along the
left of the four patch elements) and the four patch elements form a
first antenna that radiates electromagnetic energy with a first
polarization pattern of approximately a positive 45 degrees and the
second set of metal lines (along the right of the patch elements)
and the four patch elements form a second antenna that radiates
electromagnetic energy with a second polarization pattern at
approximately a negative 45 degrees, which together cumulatively
form a cross-polarization radiation pattern. Because the PCB 652 is
square with the different sets of patch elements located side by
side, the cross-polarization radiation pattern is fatter and
rounder (than the side radiation patterns) as illustrated with the
fifth radiation pattern 562 and the sixth radiation pattern 564 in
FIG. 5B. For example, the width (W.sub.2) and the length (L.sub.2)
may be the same distance. In one embodiment, that dimensions are 77
mm by 77 mm square.
[0109] With still more specificity as to the first set of metal
lines, the first metal line 653 includes multiple portions: a first
portion extending from the first patch element 654 in a first
direction to a first end; a second portion extending from the first
end in a second direction to a second end; and a third portion
extending from the second end in a third direction to the second
patch element 656. The second portion may taper from the first end
and the second end to a first center of the second portion, and the
first end and the second end may each include a clipped corner. The
second metal line 655 includes multiple portions: a fourth portion
extending from the third patch element 658 in the first direction
to a third end; a fifth portion extending from the third end in the
second direction to a fourth end; and a sixth portion extending
from the fourth end in the third direction to the fourth patch
element 660. The fifth portion may taper from the third end and the
fourth end to a second center of the fifth portion, and the third
end and the fourth end may each include a clipped corner.
[0110] The third metal line 657 includes multiple portions: a
seventh portion extending from the first center of the second
portion in the first direction to a fifth end; an eighth portion
extending from the fifth end in the second direction until a sixth
end, the eighth portion tapering from the fifth end towards the
sixth end of the eighth portion; a ninth portion extending from the
sixth end in a fourth direction to a seventh end; a tenth portion
extending from the seventh end in the third direction to an eighth
end; an eleventh portion extending from the eighth end in a fifth
direction to a ninth end; a twelfth portion extending from the
ninth end in a sixth direction, opposite the first direction, until
a tenth end, the twelfth portion tapering from the tenth end
towards the ninth end of the twelfth portion; and a thirteenth
portion extending from the tenth end in the third direction to the
second center of the fifth portion. The fifth end and the tenth end
may each include a clipped corner, and the first RF feed 671 is
disposed at a third center of the tenth portion. A second radio,
which is disposed on the main circuit board, is coupled to the
first RF feed 671.
[0111] The detailed description of the first set of metal lines
(e.g., the first metal line 653, the second metal line 655, and the
third metal line 657) applies equally to the second set of metal
lines (e.g., the fourth metal line 663, fifth metal line 665, and
sixth metal line 665), which are disposed symmetrically at the
right sides of the four patch elements 654, 656, 658, and 660.
[0112] FIG. 6C illustrates the phased array patch antenna 648 of
FIG. 6B within one of the fifth metal section 512, forming the top
chamber, or the sixth metal section 514, forming the bottom
chamber, of the MRMC network device 500 of FIG. 5A according to one
embodiment. The phased array patch antenna 648 may further include
a number of parasitic elements 684, 686, 688, and 690,
corresponding respectively to the four patch elements 654, 656,
658, and 660, retained at a predetermined distance from each
respective patch element. The surface area of each of the parasitic
elements may be about a fourth (or more) larger than its
corresponding patch element. In one example, the underlying patch
elements may be 14 mm by 14 mm and the floating, parasitic elements
may be approximately 18 mm by 18 mm. In this way, the parasitic
elements within the phased array patch antenna 648 helps increase
the gain of the electromagnetic radiation patterns in a direction
perpendicular to a first plane of with the PCB 652. Each parasitic
element provides parasitic coupling between each patch element and
a corresponding parasitic element positioned opposite the patch.
Such parasitic elements (e.g., parasitic elements 524, 526, 528,
and 530 of FIG. 5A) may also be employed with the phased array
patch antenna 621 to increase the gain and directionality of the
electromagnetic radiation patterns coming out of the sides of the
metal housing 502, e.g., perpendicular to the PCB 622. Accordingly,
the parasitic elements are sometimes referred to as parasitic
patches or director patches.
[0113] FIG. 7A illustrates a combination omnidirectional antenna
700 in which a wireless wide area network (WWAN) antenna 701 and a
wireless local area network (WLAN) antenna 725 share a common
ground element 702 on a PCB (e.g., a microstrip PCB), according to
one embodiment. The common ground element 702 may be a ground patch
element, which is positioned between the WWAN antenna 701 and the
WLAN antenna 725. In one embodiment, the WWAN antenna 701 and the
WLAN antenna 725 are adapted for simultaneous operation.
[0114] In a first embodiment, the WWAN antenna 701 may have a
planar inverted F-antenna-type structure. Rather than a ground
plane, the WWAN antenna 701 may include a first ground element 703,
which may be P-shaped, and a tapered launcher structure 706
parasitically coupled to the first ground element 703. The first
ground element 703 includes a ground feed element 703A. The tapered
launcher structure 706 may be triangular in shape include a feed
element extending opposite to the ground feed element 703A. A
hypotenuse of the triangle shaped of the tapered launcher structure
706 may oppose the P-shape of the first ground element 703, to
provide additional surface area for parasitic coupling to ground. A
first RF feed 704 is attached to the feed element of the tapered
launcher structure 706. The first RF feed 704 may be coupled to a
radio on the main circuit board (1402 in FIG. 14). The WWAN antenna
700 may further include a dual-feed arm 708, extending from the
tapered launcher structure 706, that is parasitically coupled to a
dual-parasitic arm 712. The dual-parasitic arm 712 is connected to
the common ground element 702. A parasitic element is an element of
the WWAN antenna 701 that is not driven directly by an RF feed. The
dual-feed arm 708 is fed by the first RF feed 704.
[0115] In the first embodiment, the dual-feed arm 708 may be a
folded monopole structure that includes a first L-shaped element
709 and a layered portion 710 that connects to the first L-shaped
element 709. The dual-feed arm 708 connects to the tapered launcher
structure 706 at a first end and includes the first L-shaped
element 709 at a second end opposite the first end, about a third
of the distance away from the common ground element 702. The first
L-shaped element 709 may extend about half way across a height of
the tapered launcher structure 706. The layered element 710
connects to the first L-shaped element 709 and is positioned
tightly between the tapered launcher structure 706 and the first
L-shaped element 709. The layered element 710 includes a number of
switch-back folds that are parallel to each other and to the
dual-feed arm 708. In one embodiment, the layered element 710
includes five switch-back folds, where the fifth switch-back fold
may be discontinuous. Fewer or more switch-back folds are
envisioned in alternative embodiments.
[0116] In the first embodiment, the dual-parasitic arm 712 may be a
second folded monopole antenna, connected to the common ground
element 702, which includes a second L-shaped element 713 and an
extension element 715. The dual-parasitic arm 712 connects to the
common ground element 702 at a first end, and includes the second
L-shaped element 713 at a second end opposite to the first end. The
second L-shaped element 713 is parasitically coupled to the first
L-shaped element 709 of the dual-feed arm 708, and therefore is
driven parasitically by a combination of the tapered launcher
structure 706 and the dual-feed arm 708. The extension element 715
doubles back parallel to the dual-parasitic arm 712 towards the
common ground element 702, leaving a solid element between the
second L-shaped element 709 and the extension element 715. The
current flowing within the dual-parasitic arm 712 may be
parasitically induced by the current flowing through the dual-feed
arm 708.
[0117] Further to the first embodiment, the WLAN antenna 725 may
have a self-coupled, inverted F-antenna structure. The WLAN antenna
725 includes a folded monopole structure 728 on a first side of the
PCB, and on a second side of the PCB, a grounding element 711 and a
parasitic T-shaped structure 730. The folded monopole structure 728
connects on a first end to the common ground element 702, and
includes multiple portions: a first portion that extends away from
a top of the common ground element 702 in a first direction until a
first fold; a second portion that extends from the first fold in a
second direction until a second fold; and a third portion that
extends from the second fold in a third direction, the third
direction being opposite to the first direction and thus back
towards the common ground element 702. One side of the top of the
T-shaped structure 730 is connected approximately halfway along the
first portion of the folded monopole structure 728.
[0118] In one embodiment, a second RF feed 726 is disposed to the
other side of the top of the T-shaped structure 730. The second RF
feed 726 may be coupled to a radio on the main circuit board. The
bottom leg of the T-shaped structure 730 is parasitically coupled
to the end of the third portion of the folded monopole structure
728. The grounding element 711 attaches to a bottom of the common
ground element 702 and is parasitically coupled to the RF-feed-end
of the T-shaped structure. The WLAN antenna 725 is fed at the
second RF feed 726. This combination of structures provides an
omnidirectional WLAN antenna that may radiate electromagnetic
energy at a first frequency, e.g., 2.5 GHz.
[0119] FIG. 7B illustrates a combination omnidirectional antenna
750 in which a WWAN antenna 751 and a WLAN antenna 775 share a
common ground element 702 on a PCB, according to a second
embodiment. The common ground element 702 may be a ground patch
element which is positioned between the WWAN antenna 751 and the
WLAN antenna 775. In one embodiment, the WWAN antenna 751 and the
WLAN antenna 775 are adapted for simultaneous operation.
[0120] In the second embodiment, while some of the antenna
structures are similar, others vary. The WWAN antenna 751 may still
have a planar inverted F-antenna-type structure. Rather than a
ground plane, the WWAN antenna 751 includes a second ground element
753. The second ground element 753 may be U-shaped, and include a
ground extension element 754 extending off a bottom side and a
folded monopole structure 756 extending off of a top side of the
second ground element 753. The ground extension element 754 is
oriented opposite to the folded monopole structure 756. The folded
monopole structure 756 includes multiple portions: a first portion
that extends off the top side of the second ground element 753 in a
first direction (which is the same direction as the ground
extension 754) until a first fold; a second portion extending from
the first fold in a second direction until a second fold; and a
third portion that extends from the second fold in a third
direction, the third direction being opposite to the first
direction and thus back towards the second ground element 753.
[0121] The WWAN antenna 751 may further include a dual-feed arm 758
and a dual-parasitic arm 752 that is parasitically coupled to the
dual-feed arm 758. The dual-feed arm 758 is parasitically coupled
to the second ground element 753, and includes multiple portions: a
first portion that extends from a first RF feed 755 in a fourth
direction, opposite the second direction, until a first fold; a
second portion that extends from the first fold in the first
direction until a second fold; an L-shaped element 759 that extends
from the second fold in the second direction; a layered element 760
that begins with an extension from adjacent the first fold on the
second portion, and includes multiple switch-back folds positioned
tightly between the first portion 757 and the L-shaped element 759;
and a layered extender 762 that extends off of the final
switch-back fold beyond the L-shaped element 759 in the first
direction. The first RF feed 755 may be located between the ground
extension 754 and a first end of the first portion of the dual-feed
arm 758, and may be connected from a back side of the PCB. The
first RF feed 755 may be coupled to a radio on the main circuit
board (1402 in FIG. 14). In one embodiment, the connection point of
the layered element 760 is at a mid-point of the first of the
multiple switch-backs folds. There may be six total switch-back
folds, although fewer or more switch-back folds are envisioned. The
dual-feed arm 758 may be fed by the first RF feed 755.
[0122] In the second embodiment, the dual-parasitic arm 752 is
connected to the common ground element 702 at a first end and
includes multiple portions: a first portion that extends the third
direction until a solid end element, which is parasitically coupled
to the L-shaped element 759 of the dual-feed arm 758, and the
extension element 715 that extends from the solid element in the
first direction back towards the common ground element 702. The
first portion is parallel to the extension portion 715. An end of
the extension element 715 may terminate adjacent to the common
ground element 702 in one embodiment. The current flowing within
the dual-parasitic arm 752 may be parasitically induced by the
current flowing through the dual-feed arm 758.
[0123] Further to the second embodiment, the WLAN antenna 775 may
have a planar inverted F-antenna structure, which is also connected
to the common ground element 702. The WLAN antenna includes a
folded monopole structure 778, a feed arm structure 780, and a
second ground extension 784. The folded monopole structure 778
includes multiple portions: a first portion that extends from the
common ground element 702 in the first direction to a first fold; a
second portion that extends from the first fold in the second
direction until a second fold; and a third portion that extends
from the second fold in the third direction. The feed arm structure
780 connects between a midpoint of the first portion of the folded
monopole structure 778 to a second RF feed 776. The second RF feed
776 may be coupled to a radio on the main circuit board. The second
ground extension 784 extends in the first direction from the common
ground element 702 and may connect (or be coupled) to the
RF-feed-end of the feed arm structure 780 in one embodiment. The
WLAN antenna 775 is fed at the second RF feed 776. This combination
of structures provides an omnidirectional WLAN antenna that may
radiate electromagnetic energy at a first frequency, e.g., 2.5
GHz.
[0124] FIG. 8 illustrates a foam-layer-based patch antenna 820
integrated within an chamber of the MRMC network device 500 of FIG.
5A according to an alternative embodiment. In this alternative
embodiment, the retaining of a parasitic element the predetermined
distance away from a patch may be performed using a foam material.
Foam (e.g., Syrofoam or urethane foam) has a dielectric constant of
1.01, which is very close to that of air having a dielectric
constant of 1.0.
[0125] More specifically, the foam-layer-based patch antenna 820
may include a number of layers, including but not limited to, a
conductive adhesive 822, a frame adhesive 826, a PCB with a patch
antenna 828, a third adhesive 830, a first foam layer 834, a fourth
adhesive 838, a parasitic element 844, a fifth adhesive 846, and an
optional top foam layer 848 to enclose and seal the other layers.
Note that some of these layers are optional depending on whether
the layers are adhered together or are compressed together in some
other way, e.g., via fasteners or simple compression with an outer
layer such as the top foam layer 848.
[0126] In one embodiment, the first foam layer 834 may be of a
thickness of the predetermined distance (e.g., about 3 mm in one
embodiment), and include raised strips formed into an open-face box
835 positioned on an opposite side of the first foam layer 834 from
a patch within the patch antenna 828. The parasitic element 844 is
disposed within the open-faced box of the foam layer, to act as a
parasitic antenna element to the patch. In other embodiments, the
open-face box 835 may be eliminated or some other structure may be
used to orient the parasitic element 844 to be aligned with the
patch of the patch antenna.
[0127] Further note that the alternative embodiment of FIG. 8
discloses an approach that may be employed within either or both of
the phased array patch antennas 621 and 648, e.g., to retain each
of the parasitic elements 684, 686, 688, and 690 the predetermined
distance away from the corresponding patch elements of either or
both of the phased array patch antennas 621 and 648.
[0128] FIGS. 9A, 9B, 9C, 9D, and 9E illustrate a polymer-based
patch antenna 900 within a chamber of the MRMC network device of
FIG. 5A according to an alternative embodiment. FIG. 9A is an
antenna frame 902 made of a polymer, such as Zeonex.RTM. RS420,
which has a dielectric constant of approximately 2.3. The antenna
frame 902 may be an injection molded part to include a block
retainer 904 with which to retain a parasitic element 906 as
illustrated in FIGS. 9B and 9C.
[0129] In one embodiment, the antenna frame 902 may include a
recessed portion 905 (FIG. 9B) around the block retainer 904, into
which may be disposed (and optionally adhered) a PCB 908 containing
a patch antenna (FIG. 9D). FIG. 9E is a cross-section view of a
metal section 910 that forms a chamber in which is located the
antenna frame 902 holding the parasitic element 906 a predetermined
distance from the patch of the patch antenna disposed the PCB 908.
Note that tabs on a bottom portion of the block retainer 904 may
enforce a gap of the predetermined distance between the parasitic
element 906 and the PCB 908 with a minimal amount of polymer
material, thus leaving mostly air within the gap.
[0130] In various embodiments, the polymer-based patch antenna 900
may be employed as another approach within either or both of the
phased array patch antennas 621 and 648, e.g., to retain each of
the parasitic elements 684, 686, 688, and 690 the predetermined
distance away from the corresponding patch elements of either or
both of the phased array patch antennas 621 and 648.
[0131] FIG. 10A is an exploded view of a side antenna assembly
1000, according to one embodiment. The side antenna assembly 1000
may include, but not be limited to, the phased array patch antenna
621 of FIG. 6A disposed within the recessed region of a chamber
formed by a metal section 1004. The metal section 1004 may
correspond to any of the metal sections 504, 506, 508, and 510
illustrated in FIG. 5.
[0132] The phased array patch antenna 621 may further include a
pair of conductive foam 1005A and 1005B, a first coax cable 1007A,
a second coax cable 1007B, the PCB 622, and an antenna frame 1021.
The conductive foam 1005A, 1005B may be positioned between the PCB
622 and the back wall of the metal section 1004 to help
parasitically couple the patch elements disposed on the PCB 622 to
ground (e.g., the metal section 1004 that is grounded) through the
PCB 622. The first coax cable 1007A may connect between the first
RF feed 641 and a radio on the main circuit board through a first
aperture 1003A of the metal section 1004. The second coax cable
1007B may connect between the second RF feed 645 and the radio
through a second aperture 1003B of the metal section 1004. In
various embodiments, although shown formed in the back wall, the
first aperture 1003A and the second aperture 1003B may also be
formed in any of the sidewalls of the metal section 1004.
[0133] The antenna frame 1021 may be made of any dielectric
material such as polymer (or equivalent) material, e.g.,
polycarbonate/acrylonitrile butadiene styrene (PC/ABS), which has a
dielectric constant of 3.0, or the like. The antenna frame 1021 may
be attached between at least two of the sidewalls of the metal
section such as to be oriented in a second plane parallel to the
first plane of the PCB 622, and to retain the parasitic elements
524, 526, 528, and 530 at the predetermined distance from
respective patch elements 624, 626, 628, and 630 on the PCB 622.
More specifically, the antenna frame 1021 may include a number of
frame elements, which form openings in the antenna frame 1021,
including a first frame element 1084 to retain the first parasitic
element 524, a second frame element 1086 to retain the second
parasitic element 526, a third frame element 1088 to retain the
third parasitic element 528, and a fourth frame element 1090 to
retain the fourth parasitic element 530 at the predetermined
distance from the corresponding patch elements 624, 626, 628, and
630. Each frame element may include one or more extension tabs 1095
with a depth sized to the predetermined distance. Each frame
element and extension tabs may be minimized in size to reduce the
amount of polymer-based material existing between the parasitic
elements and the patch elements, thus maximizing an amount of
parasitic coupling between the patch elements and the parasitic
elements.
[0134] FIG. 10B illustrates a completely assembled side antenna
assembly 1000, according to one embodiment. As illustrated, the
side antenna assembly 1000 has now been assembled with the phased
array patch antenna 621 and the antenna frame 1021 mutually aligned
and attached to the back wall of the metal section 1004 in the
recessed region previously mentioned. The extension tabs 1095 may
abut up against the PCB 622, thus ensuring to keep the gap defining
the predetermined distance constant. In this way, the reflective
metal of the angled sidewalls, the top sidewall, and the bottom
sidewall can now reflect the electromagnetic radiation pattern
produced by the patch elements of the phased array patch antenna
621 directionally to the outside of the metal housing 502, e.g.,
out one of the sides of the metal housing.
[0135] FIG. 11A is an exploded view of a bottom antenna assembly
1100 (which may also represent a top antenna assembly), according
to one embodiment. The bottom antenna assembly 1100 may include,
but not be limited to, the phased array patch antenna 648 of FIG.
6B disposed within the chamber formed by a metal section 1104. The
metal section 1104 may correspond to any of the fifth metal section
512, which forms the top chamber, or the sixth metal section 514,
which forms the bottom chamber, as illustrated in FIG. 5.
[0136] The phased array patch antenna 648 may further include a
pair of conductive foam 1105A and 1105B, a first coax cable 1107A,
a second coax cable 1107B, the PCB 652, and an antenna frame 1121.
The conductive foam 1105A, 1105B may be positioned between the PCB
652 and the back wall of the metal section 1104 to help
parasitically couple the patch elements disposed on the PCB 652 to
ground (e.g., the metal section 1104 that is grounded) through the
PCB 652. The first coax cable 1107A may connect between the first
RF feed 671 and a radio on the main circuit board through an
aperture 1103 of the metal section 1104. The second coax cable
1107B may connect between the second RF feed 675 and the radio also
through the aperture 1103 of the metal section 1104. Although shown
formed in the back wall, the aperture may be formed in any of the
angled sidewalls of the metal section 1104.
[0137] The antenna frame 1121 may be made of any dielectric such as
a polymer (or equivalent) material, e.g., PC/ABS or the like. The
antenna frame 1121 may be attached between at least two of the
sidewalls of the metal section 1104 such as to be oriented in a
second plane parallel to the first plane of the PCB 652, and to
retain the parasitic elements 684, 686, 688, and 690 at the
predetermined distance from respective patch elements 654, 656,
658, and 660 on the PCB 622. More specifically, the antenna frame
1121 may include a number of frame elements, including a first
frame element 1184 to retain the first parasitic element 684, a
second frame element 1186 to retain the second parasitic element
686, a third frame element 1188 to retain the third parasitic
element 688, and a fourth frame element 1190 to retain the fourth
parasitic element 690 at the predetermined distance from the
corresponding patch elements 654, 656, 658, and 660. Each frame
element may include one or more extension tabs 1195 with a depth
sized to the predetermined distance. Each frame element and
extension tabs may be minimized in size to reduce the amount of
polymer-based material existing between the parasitic elements and
the patch elements, thus maximizing an amount of parasitic coupling
between the patch elements and parasitic elements.
[0138] FIG. 11B illustrates a completely assembled bottom antenna
assembly 1100, according to one embodiment. As illustrated, the
bottom antenna assembly 1100 has now been assembled with the phased
array patch antenna 648 and the antenna frame 1121 mutually aligned
and attached to the back wall of the metal section 1104 in the
recessed region previously mentioned. The extension tabs 1195 may
abut up against the PCB 652, thus ensuring to keep the gap defining
the predetermined distance constant. In this way, the reflective
metal of the angled sidewalls can now reflect the radiation pattern
produced by the patch elements of the phased array patch antenna
648 directionally to the outside of the metal housing 502, e.g.,
out the top or the bottom of the metal housing.
[0139] FIG. 12 illustrates a partially exploded view of the MRMC
network device 500 of FIG. 5A, including two side antenna
assemblies 1000A and 1000B, the top antenna assembly 1100, and a
bottom antenna assembly 1100B, according to one embodiment. The top
antenna assembly 1100 attaches to a top of the side antenna
assemblies (four in total as illustrated in FIG. 5A) and the bottom
antenna assembly 1100B attaches to the bottom of the side antenna
assemblies. Note that the first coax cable 1007A and the second
coax cable 1007B of each of the side antenna assemblies 1000A and
1000B are fed through the apertures 1003A and 1003B, respectively,
in the back wall of each metal section 1004 of the side antenna
assemblies (FIG. 10A), although the apertures 1003A and 1003B may
alternatively be formed in a sidewall of each metal section 1004 in
alternative embodiments. Further note that the first coax cable
1107A and the second coax cable 1107B of each of the top antenna
assembly 1100 and the bottom antenna assembly 1100B are fed through
the aperture 1103 in the back wall of the metal section 1104 (FIG.
11A), although the aperture 1003 may alternatively be formed in one
of the angled sidewalls of the metal section 1104. These coax
cables may each be coupled to a radio on the main circuit board
1402, which is first illustrated in FIG. 14.
[0140] FIG. 12 further illustrates a battery 1203 attached to a
sidewall of the metal section 1004 of the side antenna assembly
1000A, a battery cable 1209 for the battery 1203, and a set of air
dams, including a first air dam 1205A, a second air dam 1205B, and
a third air dam 1205C. Each air dam is positioned between two side
antenna assemblies to block air from back flowing into a bottom
part of the metal housing 502, which will be discussed in more
detail.
[0141] FIG. 13A illustrates a first air baffle assembly 1300 that
cools a main circuit board of the MRMC network device 500 of FIG.
5A according to one embodiment. The first air baffle assembly 1300
may include a first air baffle 1302 and a first heat sink 1304. The
first heat sink 1304 is sized to fit inside of the first air baffle
1302, and the entire first air baffle assembly 1300 has a
triangular cross-section adapted to fit into half of the
rectangular inner chamber of the metal housing 502. In one
embodiment, the first air baffle 1302 and the first heat sink 1304
is formed as a single extrusion of conductive metal, e.g., for
de-sensing and additional cooling properties of the conductive
metal.
[0142] FIG. 13B illustrates a second air baffle assembly 1310 that
also cools the main circuit board of the MRMC device 500 of FIG. 5B
according to one embodiment. The second air baffle assembly 1310
may include a second air baffle 1312 and a second heat sink 1314.
The second heat sink 1314 is sized to fit inside of the second air
baffle 1312, and the entire second air baffle assembly 1310 has a
triangular cross-section adapted to fit into the other half of the
rectangular inner chamber of the metal housing 500. In one
embodiment, the second air baffle 1312 and the second heat sink
1314 is formed as a single extrusion of conductive metal, e.g., for
de-sensing and additional cooling properties of the conductive
metal.
[0143] Both the first air baffle 1302 and the second air baffle
1312 may be made of a conductive metal material, such as aluminum
or copper, or made of a polymer such as polycarbonate/acrylonitrile
butadiene styrene (PC/ABS), or the like. Both the first heat sink
1304 and the second heat sink 1314 may be made of a heat conductive
metal such as aluminum or the like.
[0144] FIG. 14 illustrates an exploded view of an air cooling
system 1400, main circuit board 1402, and support bracket 1416
according to one embodiment. There are at least six radios on the
main circuit board 1402, including a first WLAN radio 1410, a
second WLAN radio 1412 (and two more WLAN radios as well as a WiFi
2.4 GHz radio 1416 on the other side of the main circuit board 1402
that are not visible). Due to this number of power-generating
radios on the main circuit board 1402, the air cooling system 1400
has a lot of cooling to perform. In various embodiments, the air
cooling system 1400 may include the first air baffle assembly 1300,
the second air baffle assembly 1310, and a fan 1414 adapted to
attach to a first end of each of the first air baffle assembly 1300
and the second air baffle assembly 1310. The support bracket 1416
may attach to (or along) an edge of the main circuit board 1402 to
provide extension space for attachment of additional components as
will be discussed with reference to FIGS. 15A, 15B, and 15C. The
support bracket 1416 may also be attached to the second air baffle
assembly 1310.
[0145] FIG. 15A illustrates a side view of the assembled air
cooling system 1400, main circuit board 1402, and support bracket
1416 according to one embodiment. The MRMC network device 500 may
further include a communication device 1504, e.g., that supports
cellular communication via any of the cellular protocols discussed
herein, and a storage card assembly 1506. The communication device
1504 may include a WWAN radio for cellular communication. With
further reference to FIGS. 15B and 15C, the storage card assembly
1506 may include a shield cover 1508 and a storage device 1512. In
one embodiment, the shield cover 1508 is made of metal and the
storage device 1512 is a solid-state drive (SSD) card, although
other types of storage devices are envisioned. FIG. 15C is a blow
up of the encircled portion of the support bracket 1416 shown in
FIG. 15B. The shield cover 1508 may be adapted to both completely
cover (e.g., snap onto) the storage device 1512 and to securely
attach the storage device 1512 to both the support bracket 1416 and
to the storage device 1512. For example, the shield cover 1508 may
include extension tabs that form openings through which a fastener
may attach the shield cover 1508 to the support bracket 1416.
[0146] FIG. 16 illustrates a perspective view of a
partially-assembled MRMC network device 500 with placement of the
assembled air cooling system 1400, the main circuit board 1402, and
the support bracket 1416 (FIG. 15A), according to one embodiment.
Note that the assembled air cooling system 1400, the main circuit
board 1402, and the support bracket 1416 has now been positioned
within the inner chamber of the metal housing 502, with the support
bracket 1416 being located between two of the side antenna
assemblies, e.g., side antenna assembly 1000A and another side
antenna assembly that is not shown.
[0147] In various embodiments, the air cooling system 1400 includes
the air dams 1205A, 1205B, 1205C, and a fourth air dam 1205D (FIG.
18), each of which are adapted and conformed to fit between
respective of the four side antenna assemblies. For example, each
air dam may be disposed longitudinally between one of the first air
baffle assembly 1300 or the second air baffle assembly 1310 and an
intersection of two sides of the metal housing 502. The air dams
may be adapted to prevent air pushed across the first heat sink
1304 and the second heat sink 1314 from back flowing into a bottom
portion of the metal housing 502, e.g., so that air that is being
used to cool the electronics on the main circuit board 1402 and the
support bracket 1416 is not recycled hot air. In one embodiment,
the support bracket 1416 may also support a modem 1604 or other
secondary communication device.
[0148] Note that the square nature of the fan 1414 and the square
cross-section of the attached first baffle assembly 1300 and second
baffle assembly 1310 allow maximization of the sizes of the first
heat sink 1304 and the second heat sink 1314 within the inner
chamber of the metal housing 502. Furthermore, the positioning of
the fan 1414 within a center of the inner chamber of the metal
housing 502 buries the noise of the fan so that the MRMC network
device 500 is quieter during operation. Furthermore, positioning
the fan 1414 away from other components and parts of the metal
housing 502, and attaching the fan 1414 with rubber gaskets or the
like, reduces noises from vibration that may otherwise arise from a
fan that is attached to the main circuit board 1402 or is in
contact with components that easily vibrate.
[0149] In various embodiments, the main circuit board 1402 of the
MRMC network device 500 may further include a number of RF shields
and coax cable retention systems 1607, which are adapted to both
shield the ends of the coax cables from other RF electromagnetic
energy and to retain the end of the coax cables in place, which is
discussed in more detail with reference to FIGS. 17A and 17B.
[0150] FIG. 17A illustrates an exploded view of an RF shield and
coax cable retention system 1607 according to one embodiment. FIG.
17B illustrates an assembled view of the RF shield and coax cable
retention system 17B of FIG. 17A. The RF shield and coax cable
retention system 1607 may include, but not be limited to, a shield
cover 1710, a foam piece 1712, a shielding fence 1720, a first coax
connector 1725A, and a second coax connector 1725B, which may be
assembled to provide isolation and retention for ends of a first
coax cable 1707A and the second coax cable 1707B.
[0151] The shielding fence 1720, which is attached to the main
circuit board 1402, may further include a pair of bridge structures
1721A and 1721B, a number of clamps 1723, and a pair of guides
1724A and 1724B. The bridges structures 1721A and 1721B may provide
a path for metal lines on the main circuit board 1402 to get past
the shielding fence 1720 and connect to respective of the first
coax connector 1725A and the second coax connector 1725B,
respectively. These metal lines may connect to a radio, for
example, located elsewhere on the main circuit board 1402.
[0152] In various embodiments, the coax cables 1707A and 1707B may
first be attached to respective of the first coax connector 1725A
and second coax connector 1725B as illustrated in FIG. 17B. The
ends of the coax cables may be oriented at a 90-degree angle with
respect to the coax cables to facilitate these connections. The
foam piece 1712 may fit inside of the shield cover 1710, which may
be snapped into position onto the clamps 1723 located around the
perimeter of the shielding fence 1720. The pair of guides 1724A and
1724B may be half clamps that guide the shield cover into position
for snapping into place. The biasing of the pressure between the
foam piece 1712 and the clamps 1723 provides secure retention of
the coax cables 1707A and 1707B within the RF shield and coax cable
retention system 1607 once attached to respective of the first coax
connector 1725A and the second coax connector 1725B.
[0153] FIG. 18 illustrates an almost-complete assembly of the MRMC
network device 500 according to one embodiment. Further to the
discussion with reference to FIG. 16, note that a fourth side
antenna assembly 1000D has been added and a third side antenna
assembly 1000C is about to be added to the metal housing 502 to
complete the metal housing 502 of the MRMC network device 500.
While the third air dam 1205C will be located between the second
and third side antenna assemblies, an additional air dam 1205D has
been added to be located between the third and fourth side antenna
assemblies. The air cooling system 1400 remain in place, oriented
from bottom to top within the inner chamber of the metal housing
502, such that air pulled from a bottom of the inner chamber and
metal housing is pushed out of the upper part of the inner chamber
and the metal housing. As discussed, the air dams 1205C and 1205D
provide a means by which to substantially block air back flow from
the top to the bottom of the inner chamber and metal housing.
[0154] With further reference to FIG. 18, the first combination
omnidirectional antenna 540 and the second combination
omnidirectional antenna 545 may be attached to top sidewalls of
adjacent metal sections, e.g., to the top of the third side antenna
assembly 1000C and to the top of the second side antenna assembly
1000B, respectively.
[0155] FIG. 19A illustrates a complete assembly of the MRMC network
device 500 according to one embodiment. Further to the discussion
with reference to FIG. 18, the first combination omnidirectional
antenna 540 has been attached to the top of the third side antenna
assembly 1000C, and the third side antenna assembly 1000C has been
put in place to complete assembly of the metal housing 502 of the
MRMC network device 500.
[0156] FIG. 19B illustrates the complete assembly of the MRMC
network device 500 together with a chassis 1900 placed over the
outside of the metal housing 502 according to one embodiment. The
chassis 1900 may include a rubber foot 1902, a first side portion
1904, a second side portion 1906, and a top portion 1910. The
rubber foot 1902 may be glued or otherwise adhered to the outside
of the bottom antenna assembly 1100B. The first side portion 1904
may include venting holes through which to pull air, e.g., when the
fan 1414 runs to provide cooling. The second side portion 1906 may
be solid and generally coincide with the area above the air dams
1205A, 1205B, 1205C, and 1205D of the air cooling system 1400,
e.g., so that air that pulled through the first side portion 1904
is funneled out of the top portion 1910. Accordingly, the top
portion 1910 includes exhaust holes through which to push out air
exhaust after exiting the top of the inner chamber and top of the
metal housing 502.
[0157] The first side portion 1904 of the chassis 1900 may further
include a number of ports, including but not limited to, a light
indicator 10, a Universal Serial Bus (USB) port 20, a first
Ethernet port 30A, a second Ethernet port 30B, and a locking
mechanism 40. The light indicator 10 may facilitate communication
of troubleshooting codes to users. The locking mechanism 40 may, in
one embodiment, be a Kensington.RTM. lock slot. Either of the first
Ethernet port 30A or the second Ethernet port 30B may correspond to
the Ethernet port 444 discussed with reference to FIG. 4.
[0158] In the above description, numerous details are set forth. It
will be apparent, however, to one of ordinary skill in the art
having the benefit of this disclosure, that embodiments may be
practiced without these specific details. In some instances,
well-known structures and devices are shown in block diagram form,
rather than in detail, in order to avoid obscuring the
description.
[0159] Some portions of the detailed description are presented in
terms of algorithms and symbolic representations of operations on
data bits within a computer memory. These algorithmic descriptions
and representations are the means used by those skilled in the data
processing arts to most effectively convey the substance of their
work to others skilled in the art. An algorithm is here, and
generally, conceived to be a self-consistent sequence of steps
leading to a desired result. The steps are those requiring physical
manipulations of physical quantities. Usually, though not
necessarily, these quantities take the form of electrical or
magnetic signals capable of being stored, transferred, combined,
compared, and otherwise manipulated. It has proven convenient at
times, principally for reasons of common usage, to refer to these
signals as bits, values, elements, symbols, characters, terms,
numbers or the like.
[0160] It should be borne in mind, however, that all of these and
similar terms are to be associated with the appropriate physical
quantities and are merely convenient labels applied to these
quantities. Unless specifically stated otherwise as apparent from
the above discussion, it is appreciated that throughout the
description, discussions utilizing terms such as "inducing,"
"parasitically inducing," "radiating," "detecting," determining,"
"generating," "communicating," "receiving," "disabling," or the
like, refer to the actions and processes of a computer system, or
similar electronic computing device, that manipulates and
transforms data represented as physical (e.g., electronic)
quantities within the computer system's registers and memories into
other data similarly represented as physical quantities within the
computer system memories or registers or other such information
storage, transmission or display devices.
[0161] Embodiments also relate to an apparatus for performing the
operations herein. This apparatus may be specially constructed for
the required purposes, or it may comprise a general-purpose
computer selectively activated or reconfigured by a computer
program stored in the computer. Such a computer program may be
stored in a computer readable storage medium, such as, but not
limited to, any type of disk including floppy disks, optical disks,
CD-ROMs and magnetic-optical disks, read-only memories (ROMs),
random access memories (RAMs), EPROMs, EEPROMs, magnetic or optical
cards, or any type of media suitable for storing electronic
instructions.
[0162] The algorithms and displays presented herein are not
inherently related to any particular computer or other apparatus.
Various general-purpose systems may be used with programs in
accordance with the teachings herein, or it may prove convenient to
construct a more specialized apparatus to perform the required
method steps. The required structure for a variety of these systems
will appear from the description below. In addition, the present
embodiments are not described with reference to any particular
programming language. It will be appreciated that a variety of
programming languages may be used to implement the teachings of the
present invention as described herein. It should also be noted that
the terms "when" or the phrase "in response to," as used herein,
should be understood to indicate that there may be intervening
time, intervening events, or both before the identified operation
is performed.
[0163] It is to be understood that the above description is
intended to be illustrative, and not restrictive. Many other
embodiments will be apparent to those of skill in the art upon
reading and understanding the above description. The scope of the
present embodiments should, therefore, be determined with reference
to the appended claims, along with the full scope of equivalents to
which such claims are entitled.
* * * * *